{"cve":"CVE-2026-102268","nvd":{"published":"2026-09-28T21:17:14.600","modified":"2026-10-07T20:25:03.030","status":"Analyzed","description":"PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, is_pem_format in jwt/utils.py is affected because is_pem_format does not recognize every PEM representation accepted by the cryptography loader. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a mutated public-key PEM as raw key bytes. As a result, HMACAlgorithm.prepare_key treats the unrecognized asymmetric public key as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":9.1},"cwes":["CWE-347"],"references":["https://github.com/jpadilla/pyjwt/commit/8b4e233a22206b34ec1186e912e75c0b2396ac07","https://github.com/jpadilla/pyjwt/releases/tag/2.14.0","https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9","https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9"],"products":["pyjwt_project:pyjwt"],"source":"nvd","synced_at":"2026-10-19T22:56:48.555445741+00:00"},"epss":{"cve":"CVE-2026-102268","score":0.00236,"percentile":0.14428,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-ffc3-869f-jxw9","url":"https://osv.dev/vulnerability/GHSA-ffc3-869f-jxw9","summary":"PyJWT: Asymmetric-PEM detection bypass: whitespace/line-ending-mutated public keys skip the HS/asymmetric confusion guard","modified":"2026-10-01T17:55:42.096970476Z","packages":[{"ecosystem":"PyPI","name":"pyjwt","purl":"pkg:pypi/pyjwt","ranges":["<2.14.0"],"fixed":["2.14.0"]}]},{"id":"PYSEC-2026-4145","url":"https://osv.dev/vulnerability/PYSEC-2026-4145","summary":"PyJWT: Asymmetric-PEM detection bypass: whitespace/line-ending-mutated public keys skip the HS/asymmetric confusion guard","modified":"2026-10-01T17:45:17.856341315Z","packages":[{"ecosystem":"PyPI","name":"pyjwt","purl":"pkg:pypi/pyjwt","ranges":["<2.14.0"],"fixed":["2.14.0"]}]}],"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."]}