Answer in brief
CVE-2021-29443 records a Medium severity (CVSS 5.9) vulnerability in Padding Oracle Attack due to Observable Timing Discrepancy in jose. The current sources do not mark it as known exploited. The current feed maps panva/jose (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 5.9. 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 panva/jose (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| panva/josegeneric | <1.28.1 || >=2.0.0 <2.0.5 || >=3.0.0 <3.11.4 | 1.28.1, 2.0.5, 3.11.4 |
Published upstream
Apr 16, 2021
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jun 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 22, 2026
jose is an npm library providing a number of cryptographic operations. In vulnerable versions AES_CBC_HMAC_SHA2 Algorithm (A128CBC-HS256, A192CBC-HS384, A256CBC-HS512) decryption would always execute both HMAC tag verification and CBC decryption, if either failed `JWEDecryptionFailed` would be thrown. A possibly observable difference in timing when padding error would occur while decrypting the ciphertext makes a padding oracle and an adversary might be able to make use of that oracle to decrypt data without knowing the decryption key by issuing on average 128*b calls to the padding oracle (where b is the number of bytes in the ciphertext block). All major release versions have had a patch released which ensures the HMAC tag is verified before performing CBC decryption. The fixed versions are `^1.28.1 || ^2.0.5 || >=3.11.4`. Users should upgrade their v1.x dependency to ^1.28.1, their v2.x dependency to ^2.0.5, and their v3.x dependency to ^3.11.4. Thanks to Jason from Microsoft Vulnerability Research (MSVR) for bringing this up and Eva Sarafianou (@esarafianou) for helping to score this advisory.
Quoted source text, attributed separately from HOL analysis.