VDB
CVE-2026-49852
CVE-2026-49852
PUBLISHED
CVSS 8.7 HIGH
Reported by GitHub_M · Published July 17, 2026
joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.6.8, joserfc.jwt.decode accepts attacker-forged HMAC-signed tokens when the caller-supplied verification key is the empty string or None, because HMACAlgorithm.sign and HMACAlgorithm.verify in src/joserfc/_rfc7518/jws_algs.py pass the output of OctKey.get_op_key(...) to hmac.new(...) and OctKey.import_key in src/joserfc/_rfc7518/oct_key.py only emits a SecurityWarning for keys shorter than 14 bytes without rejecting zero-length input. This issue is fixed in version 1.6.8.
Risk Scores
CVSS 4.0
8.7
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| authlib | joserfc | < 1.6.8 |
| chainguard | airflow-3 | 0, 0, 0 |
| authlib | joserfc | < 1.6.8, < 1.6.8 |
| wolfi | airflow-3 | 0, 0, 0 |
| chainguard | localstack | 0, 0, 0 |
Timeline
- Jul 2, 2026 CVE Published
- Jul 18, 2026 EPSS Score
- Jul 18, 2026 Security Advisory
- Aug 7, 2026 EPSS Score
References
- https://github.com/authlib/joserfc/security/advisories/GHSA-gg9x-qcx2-xmrh x_refsource_CONFIRM
- https://github.com/authlib/joserfc/commit/86d00910b2b2d2d07503fee9b572906daefab7f1 x_refsource_MISC
- https://github.com/authlib/joserfc/releases/tag/1.6.8 x_refsource_MISC