FKIE_CVE-2025-65015

Vulnerability from fkie_nvd - Published: 2025-11-18 23:15 - Updated: 2025-11-19 19:14
Severity ?
9.2 (Critical) - 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
Summary
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.
References
security-advisories@github.comhttps://github.com/authlib/joserfc/commit/63932f169d924caffafa761af2122b82059017f7
security-advisories@github.comhttps://github.com/authlib/joserfc/commit/673c8743fd0605b0e1de6452be6cba75f44e466b
security-advisories@github.comhttps://github.com/authlib/joserfc/releases/tag/1.3.5
security-advisories@github.comhttps://github.com/authlib/joserfc/releases/tag/1.4.2
security-advisories@github.comhttps://github.com/authlib/joserfc/security/advisories/GHSA-frfh-8v73-gjg4
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/authlib/joserfc/security/advisories/GHSA-frfh-8v73-gjg4
Impacted products
Vendor Product Version
To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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 \u2014 or entirely absent \u2014 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."
    }
  ],
  "id": "CVE-2025-65015",
  "lastModified": "2025-11-19T19:14:59.327",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.2,
          "baseSeverity": "CRITICAL",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2025-11-18T23:15:56.513",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/authlib/joserfc/commit/63932f169d924caffafa761af2122b82059017f7"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/authlib/joserfc/commit/673c8743fd0605b0e1de6452be6cba75f44e466b"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/authlib/joserfc/releases/tag/1.3.5"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/authlib/joserfc/releases/tag/1.4.2"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/authlib/joserfc/security/advisories/GHSA-frfh-8v73-gjg4"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/authlib/joserfc/security/advisories/GHSA-frfh-8v73-gjg4"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}


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