{"cve":"CVE-2026-54431","nvd":{"published":"2026-07-02T11:16:17.123","modified":"2026-10-25T21:10:00.770","status":"Deferred","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.\n\nThis issue was fixed in version 2.3.0","cvss_v4":{"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","score":5.1},"cvss_v3":null,"cwes":["CWE-358"],"references":["https://cert.pl/en/posts/2026/07/CVE-2026-54430","https://github.com/OpenIDC/liboauth2","https://github.com/OpenIDC/liboauth2/commit/c0b57152ed6a0af33aeb04a60bd7f5bff5ab8800"],"products":[],"source":"nvd","synced_at":"2026-10-25T23:44:34.550481224+00:00"},"epss":{"cve":"CVE-2026-54431","score":0.00178,"percentile":0.07323,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}