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

CVE-2026-49852 is fixed in 2 products on 1 platform, first by OPENSUSE-SU-2026:21263-1, released July 6, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-49852
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0017
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 6, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | joserfc Debian 14 | 1.6.8-1 | [DEBIAN-CVE-2026-49852](https://patchblox.com/security/data/fix/linux/debian-cve-2026-49852.md) | Jul 19, 2026 |
| Linux | python-joserfc opensuse-leap 16.0 | 1.1.0-bp160.3.1 | [OPENSUSE-SU-2026:21263-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21263-1.md) | Jul 6, 2026 |

---

Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.