Answer in brief
CVE-2026-28802 records a Critical severity (CVSS 9.8) vulnerability in Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification. The current sources do not mark it as known exploited. The current feed maps authlib/authlib (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-28802 records a Critical severity (CVSS 9.8) vulnerability in Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification. The current sources do not mark it as known exploited. The current feed maps authlib/authlib (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 9.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps authlib/authlib (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| authlib/authlibgeneric | >= 1.6.5, < 1.6.7 | Not reported |
Published upstream
Mar 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 20, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 1, 2026
Authlib is a Python library which builds OAuth and OpenID Connect servers. From version 1.6.5 to before version 1.6.7, previous tests involving passing a malicious JWT containing alg: none and an empty signature was passing the signature verification step without any changes to the application code when a failure was expected.. This issue has been patched in version 1.6.7.
Quoted source text, attributed separately from HOL analysis.
CVSS is 9.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps authlib/authlib (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| authlib/authlibgeneric | >= 1.6.5, < 1.6.7 | Not reported |
Published upstream
Mar 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 20, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 1, 2026
Authlib is a Python library which builds OAuth and OpenID Connect servers. From version 1.6.5 to before version 1.6.7, previous tests involving passing a malicious JWT containing alg: none and an empty signature was passing the signature verification step without any changes to the application code when a failure was expected.. This issue has been patched in version 1.6.7.
Quoted source text, attributed separately from HOL analysis.