{"id":"CVE-2026-102270","summary":"PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.","details":"PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT is_pem_format is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matching END marker. As a result, is_pem_format performs unbounded backtracking while searching for a PEM end marker. Consequently, an attacker can cause intensive CPU consumption. This issue is fixed in version 2.14.0.","aliases":["GHSA-jwrc-g2q2-pq5p"],"modified":"2026-09-30T11:30:30.255848371Z","published":"2026-09-28T20:29:24.479Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102270.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-1333"]},"references":[{"type":"WEB","url":"https://github.com/jpadilla/pyjwt/releases/tag/2.14.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102270.json"},{"type":"ADVISORY","url":"https://github.com/jpadilla/pyjwt/security/advisories/GHSA-jwrc-g2q2-pq5p"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-102270"},{"type":"FIX","url":"https://github.com/jpadilla/pyjwt/commit/8b4e233a22206b34ec1186e912e75c0b2396ac07"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/jpadilla/pyjwt","events":[{"introduced":"0"},{"fixed":"8b4e233a22206b34ec1186e912e75c0b2396ac07"},{"fixed":"c6fe464b356ff4b1ebc9ba62172d331a40aa27df"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"2.14.0"}]}}],"versions":["2.13.0","2.12.1","2.12.0","2.11.0","2.10.1","2.10.0","2.9.0","2.8.0","2.7.0","2.6.0","2.5.0","2.4.0","2.3.0","2.2.0","2.1.0","2.0.1","2.0.0","2.0.0a2","2.0.0a1","1.7.1","1.7.0","1.6.4","1.6.3","1.6.1","1.6.0","1.5.3","1.5.2","1.5.1","1.5.0","1.4.2","1.4.1","1.4.0","1.3.0","1.2.0","1.1.0","1.0.1","1.0.0","0.4.3","0.4.2","0.4.1","0.4.0","0.3.2","0.3.1","0.3.0","0.2.3","0.2.2","0.2.0","0.1.9","0.1.6"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-102270.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H"}]}