CVE catalog
CVE-2026-54431
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 r
- Severity
- Medium · CVSS 5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.18% · Oct 25, 2026
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
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | liboauth2 | sid | 2.4.0-1 | fixed |
| Debian | liboauth2 | forky | 2.4.0-1 | fixed |
| Debian | liboauth2 | trixie | 2.1.0-2 | vulnerable |
| Debian | liboauth2 | bookworm | 1.4.5.4-1 | vulnerable |
| Cpe | liboauth2 | Not reported | Not reported | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | liboauth2 | source | sid | 2.3.0-1 | not yet assigned | Not reported | Not reported |
| Debian | liboauth2 | source | forky | 2.3.0-1 | not yet assigned | Not reported | Not reported |
| Debian | liboauth2 | source | trixie | (unfixed) | not yet assigned | Not reported | Not reported |
| Debian | liboauth2 | source | bookworm | (unfixed) | not yet assigned | Not reported | Not reported |
Notes
[trixie] liboauth2: Minor issue [bookworm] liboauth2: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [liboauth2-0]Affected
Source package: [liboauth2]
Details (2)
1.4.5.4-1· amd64 · bookwormAffected
nvd · liboauth2 · debian · bookworm; nvd · liboauth2 · debian · 12
1.4.5.4-1· arm64 · bookwormAffected
nvd · liboauth2 · debian · bookworm; nvd · liboauth2 · debian · 12
- [liboauth2-apache0]Affected
Source package: [liboauth2]
Details (2)
1.4.5.4-1· amd64 · bookwormAffected
nvd · liboauth2 · debian · bookworm; nvd · liboauth2 · debian · 12
1.4.5.4-1· arm64 · bookwormAffected
nvd · liboauth2 · debian · bookworm; nvd · liboauth2 · debian · 12
- [liboauth2-apache-dev]Affected
Source package: [liboauth2]
Details (2)
1.4.5.4-1· amd64 · bookwormAffected
nvd · liboauth2 · debian · bookworm; nvd · liboauth2 · debian · 12
1.4.5.4-1· arm64 · bookwormAffected
nvd · liboauth2 · debian · bookworm; nvd · liboauth2 · debian · 12
- [liboauth2-dev]Affected
Source package: [liboauth2]
Details (2)
1.4.5.4-1· amd64 · bookwormAffected
nvd · liboauth2 · debian · bookworm; nvd · liboauth2 · debian · 12
1.4.5.4-1· arm64 · bookwormAffected
nvd · liboauth2 · debian · bookworm; nvd · liboauth2 · debian · 12
[Debian 13 (Trixie)]
- [liboauth2-0]Affected
Source package: [liboauth2]
Details (2)
2.1.0-2· amd64 · trixieAffected
nvd · liboauth2 · debian · 13
2.1.0-2· arm64 · trixieAffected
nvd · liboauth2 · debian · 13
- [liboauth2-apache0]Affected
Source package: [liboauth2]
Details (2)
2.1.0-2· amd64 · trixieAffected
nvd · liboauth2 · debian · 13
2.1.0-2· arm64 · trixieAffected
nvd · liboauth2 · debian · 13
- [liboauth2-apache-dev]Affected
Source package: [liboauth2]
Details (2)
2.1.0-2· amd64 · trixieAffected
nvd · liboauth2 · debian · 13
2.1.0-2· arm64 · trixieAffected
nvd · liboauth2 · debian · 13
- [liboauth2-dev]Affected
Source package: [liboauth2]
Details (2)
2.1.0-2· amd64 · trixieAffected
nvd · liboauth2 · debian · 13
2.1.0-2· arm64 · trixieAffected
nvd · liboauth2 · debian · 13
Observed:
References
- [https://cert.pl/en/posts/2026/07/CVE-2026-54430]
- [https://github.com/OpenIDC/liboauth2]
- [https://github.com/OpenIDC/liboauth2/commit/c0b57152ed6a0af33aeb04a60bd7f5bff5ab8800]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-54431]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-54431]
- [https://security-tracker.debian.org/tracker/CVE-2026-54431]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-54431.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]