{"cve":"CVE-2026-102270","nvd":{"published":"2026-09-28T21:17:14.943","modified":"2026-10-06T18:46:19.343","status":"Analyzed","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H","score":4.9},"cwes":["CWE-1333"],"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-jwrc-g2q2-pq5p","https://github.com/jpadilla/pyjwt/security/advisories/GHSA-jwrc-g2q2-pq5p"],"products":["pyjwt_project:pyjwt"],"source":"nvd","synced_at":"2026-10-19T22:56:48.555445741+00:00"},"epss":{"cve":"CVE-2026-102270","score":0.00246,"percentile":0.15645,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-jwrc-g2q2-pq5p","url":"https://osv.dev/vulnerability/GHSA-jwrc-g2q2-pq5p","summary":"PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.","modified":"2026-10-01T17:55:44.209063147Z","packages":[{"ecosystem":"PyPI","name":"pyjwt","purl":"pkg:pypi/pyjwt","ranges":["<2.14.0"],"fixed":["2.14.0"]}]},{"id":"PYSEC-2026-4148","url":"https://osv.dev/vulnerability/PYSEC-2026-4148","summary":"PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.","modified":"2026-10-01T17:45:15.991735466Z","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."]}