{"cve":"CVE-2026-48522","nvd":{"published":"2026-05-28T16:16:29.150","modified":"2026-10-26T13:10:00.140","status":"Modified","description":"PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient passes its uri argument directly to urllib.request.urlopen() which uses Python stdlib's default OpenerDirector registering HTTPHandler, HTTPSHandler, FTPHandler, FileHandler, and DataHandler. There is currently no documented option to restrict which schemes PyJWKClient will fetch. If an application's jku URL ingestion path accepts attacker-influenced URLs (e.g., from JWT header, configuration file, OAuth flow parameter), the attacker can cause PyJWKClient to read arbitrary local files via file:// (SSRF on local filesystem), cause PyJWKClient to attempt FTP / data-URI fetches (broader SSRF surface), or forge tokens that PyJWT verifies as valid. The library does not directly return non-HTTP(S) URI contents to the attacker; the chained \"plant a JWKS to forge tokens\" scenario described in the original report requires additional application-layer flaws (attacker write access to a filesystem path, untrusted jku derivation) that this fix does not address. 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:R/S:U/C:L/I:L/A:N","score":4.2},"cwes":["CWE-441","CWE-918"],"references":["https://github.com/jpadilla/pyjwt/security/advisories/GHSA-993g-76c3-p5m4","https://github.com/jpadilla/pyjwt/security/advisories/GHSA-993g-76c3-p5m4"],"products":["pyjwt_project:pyjwt"],"source":"nvd","synced_at":"2026-10-26T13:39:24.642594360+00:00"},"epss":{"cve":"CVE-2026-48522","score":0.00222,"percentile":0.12627,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-993g-76c3-p5m4","url":"https://osv.dev/vulnerability/GHSA-993g-76c3-p5m4","summary":"PyJWKClient: missing scheme allowlist enables CVE-2024-21643-class SSRF + token forgery via file://, ftp://, data: schemes","modified":"2026-09-10T03:50:49.179286182Z","packages":[{"ecosystem":"PyPI","name":"pyjwt","purl":"pkg:pypi/pyjwt","ranges":[">=2.0.0 <2.13.0"],"fixed":["2.13.0"]}]},{"id":"PYSEC-2026-175","url":"https://osv.dev/vulnerability/PYSEC-2026-175","summary":"","modified":"2026-06-02T12:15:09.282275410Z","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."]}