High 8.7Published Jul 17, 2026

CVE-2026-49852joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards.

Updated under an hour ago (2026-10-19 07:00 UTC)

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Exploited in the last 30 days

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.

CVSS: 8.7 HIGH (v4.0, NVD)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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness (CWE): CWE-287, CWE-326, CWE-1391
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Deferred
Record last updated: Jul 23, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

No affected products are listed yet.

References

https://github.com/authlib/joserfc/commit/86d00910b2b2d2d07503fee9b572906daefab7f1
https://github.com/authlib/joserfc/releases/tag/1.6.8
https://github.com/authlib/joserfc/security/advisories/GHSA-gg9x-qcx2-xmrh

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.