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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2025-65015 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
CVSS-B 9.2 CRITICAL
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

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/authlib/joserfc/commit/63932f169d924caffafa761af2122b82059017f7 GitHub, Inc.
https://github.com/authlib/joserfc/commit/673c8743fd0605b0e1de6452be6cba75f44e466b GitHub, Inc.
https://github.com/authlib/joserfc/releases/tag/1.3.5 GitHub, Inc.
https://github.com/authlib/joserfc/releases/tag/1.4.2 GitHub, Inc.
https://github.com/authlib/joserfc/security/advisories/GHSA-frfh-8v73-gjg4 GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-770 Allocation of Resources Without Limits or Throttling GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-65015
NVD Published Date:
11/18/2025
NVD Last Modified:
11/18/2025
Source:
GitHub, Inc.