Description
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.
Analysis and contextual insights are available on OpenCVE Cloud.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
Sign in to view the affected projects.
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-gg9x-qcx2-xmrh | joserfc: HS256/HS384/HS512 verify accepts empty/nil HMAC key (cross-language sibling of CVE-2026-45363) |
References
History
Fri, 17 Jul 2026 20:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Authlib
Authlib joserfc |
|
| Vendors & Products |
Authlib
Authlib joserfc |
Fri, 17 Jul 2026 19:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | joserfc: HS256/HS384/HS512 verify accepts empty/nil HMAC key (cross-language sibling of CVE-2026-45363) | |
| Weaknesses | CWE-1391 CWE-287 CWE-326 |
|
| References |
| |
| Metrics |
cvssV4_0
|
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-07-17T19:14:58.019Z
Reserved: 2026-06-01T22:03:19.640Z
Link: CVE-2026-49852
No data.
No data.
No data.
OpenCVE Enrichment
Updated: 2026-07-17T20:30:03Z
Github GHSA