# CVE-2026-54431: liboauth2: In liboauth2 the Demonstrating Proof-of-Possession (DPoP) verifier accepts a proof whose JSON Web Key (jwk) header co...

CVE-2026-54431 is fixed in liboauth2 on 1 platform by DEBIAN-CVE-2026-54431 (version 2.3.0-1), released July 3, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-54431
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0018
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 2, 2026

## Description

In liboauth2 the Demonstrating Proof-of-Possession (DPoP) verifier accepts a proof whose JSON Web Key (jwk) header contains private key material. RFC 9449 section 4.3 step 7 requires the verifier to reject such a proof but oauth2_token_verify() function returns success for a malformed DPoP proof that embeds the private Elliptic Curve (EC) key in the header.  This issue was fixed in version 2.3.0

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | liboauth2 Debian 14 | 2.3.0-1 | [DEBIAN-CVE-2026-54431](https://patchblox.com/security/data/fix/linux/debian-cve-2026-54431.md) | Jul 3, 2026 |

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Data as of 2026-11-09T19:38:12Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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