{"cve":"CVE-2026-48524","nvd":{"published":"2026-05-28T16:16:29.403","modified":"2026-10-26T13:10:00.140","status":"Analyzed","description":"PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient.get_signing_key() forces a fresh HTTP request to the JWKS endpoint for every JWT with an unknown kid value, with no rate limiting. Since kid comes from the unverified token header, an attacker can trigger unlimited outbound requests. The vulnerability surfaces only when a JWKS fetch fails; an attacker can attempt to provoke that with sustained unknown-kid traffic, but the outcome depends on upstream JWKS-endpoint behavior (rate limiting, transient errors) which is beyond the attacker's control. This vulnerability is fixed in 2.13.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","score":3.7},"cwes":["CWE-460","CWE-755"],"references":["https://github.com/jpadilla/pyjwt/security/advisories/GHSA-fhv5-28vv-h8m8"],"products":["pyjwt_project:pyjwt"],"source":"nvd","synced_at":"2026-10-26T13:39:24.642594360+00:00"},"epss":{"cve":"CVE-2026-48524","score":0.004,"percentile":0.33999,"date":"2026-10-26"},"kev":null,"osv":[{"id":"GHSA-fhv5-28vv-h8m8","url":"https://osv.dev/vulnerability/GHSA-fhv5-28vv-h8m8","summary":"PyJWKClient unbounded JWKS endpoint requests via attacker-controlled kid values (DoS)","modified":"2026-09-10T03:50:49.375741307Z","packages":[{"ecosystem":"PyPI","name":"pyjwt","purl":"pkg:pypi/pyjwt","ranges":[">=2.0.0 <2.13.0"],"fixed":["2.13.0"]}]},{"id":"PYSEC-2026-177","url":"https://osv.dev/vulnerability/PYSEC-2026-177","summary":"","modified":"2026-06-02T12:15:10.363704191Z","packages":[{"ecosystem":"PyPI","name":"pyjwt","purl":"pkg:pypi/pyjwt","ranges":["<2.13.0"],"fixed":["2.13.0"]}]}],"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."]}