{"cve":"CVE-2025-65015","nvd":{"published":"2025-11-18T23:15:56.513","modified":"2026-10-18T20:10:00.110","status":"Analyzed","description":"joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. In versions from 1.3.3 to before 1.3.5 and from 1.4.0 to before 1.4.2, the ExceededSizeError exception messages are embedded with non-decoded JWT token parts and may cause Python logging to record an arbitrarily large, forged JWT payload. In situations where a misconfigured — or entirely absent — production-grade web server sits in front of a Python web application, an attacker may be able to send arbitrarily large bearer tokens in the HTTP request headers. When this occurs, Python logging or diagnostic tools (e.g., Sentry) may end up processing extremely large log messages containing the full JWT header during the joserfc.jwt.decode() operation. The same behavior also appears when validating claims and signature payload sizes, as the library raises joserfc.errors.ExceededSizeError() with the full payload embedded in the exception message. Since the payload is already fully loaded into memory at this stage, the library cannot prevent or reject it. This issue has been patched in versions 1.3.5 and 1.4.2.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H","score":9.2},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-770"],"references":["https://github.com/authlib/joserfc/commit/63932f169d924caffafa761af2122b82059017f7","https://github.com/authlib/joserfc/commit/673c8743fd0605b0e1de6452be6cba75f44e466b","https://github.com/authlib/joserfc/releases/tag/1.3.5","https://github.com/authlib/joserfc/releases/tag/1.4.2","https://github.com/authlib/joserfc/security/advisories/GHSA-frfh-8v73-gjg4"],"products":["hsiaoming:joserfc"],"source":"nvd","synced_at":"2026-10-19T22:16:02.354564667+00:00"},"epss":{"cve":"CVE-2025-65015","score":0.0044,"percentile":0.37929,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-frfh-8v73-gjg4","url":"https://osv.dev/vulnerability/GHSA-frfh-8v73-gjg4","summary":"joserfc has Possible Uncontrolled Resource Consumption Vulnerability Triggered by Logging Arbitrarily Large JWT Token Payloads","modified":"2026-09-10T03:50:30.957378273Z","packages":[{"ecosystem":"PyPI","name":"joserfc","purl":"pkg:pypi/joserfc","ranges":[">=1.3.3 <1.3.5"],"fixed":["1.3.5"]},{"ecosystem":"PyPI","name":"joserfc","purl":"pkg:pypi/joserfc","ranges":[">=1.4.0 <1.4.2"],"fixed":["1.4.2"]}]},{"id":"PYSEC-2026-361","url":"https://osv.dev/vulnerability/PYSEC-2026-361","summary":"joserfc has Possible Uncontrolled Resource Consumption Vulnerability Triggered by Logging Arbitrarily Large JWT Token Payloads","modified":"2026-07-02T13:00:08.094018503Z","packages":[{"ecosystem":"PyPI","name":"joserfc","purl":"pkg:pypi/joserfc","ranges":[">=1.3.3 <1.3.5",">=1.4.0 <1.4.2"],"fixed":["1.3.5","1.4.2"]}]}],"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."]}