p PatchFirst

CVE-2026-75509

CVE-2026-75509 · joserfc claim-validation bypass via array-typed single-string claims (iss/sub/jti)

This page contains facts from public vulnerability sources. Check the original advisory before updating.

joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to version 1.7.3, JWTClaimsRegistry applies membership matching to list-valued iss and sub claims, allowing an array-valued iss that contains the expected issuer to pass an intended equality check and enabling issuer-validation bypass. This issue is fixed in version 1.7.3.

CVSS 6.5 · Medium · EPSS 0.1% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • joserfc

    Versions
    • < 1.7.3: Affected

    No fix published

  • joserfc Debian:13

    Versions
    • 1.1.0-1
    • 1.2.0-1
    • 1.2.2-1
    • 1.3.1-1
    • 1.3.2-1
    • 1.3.4-1
    • 1.4.0-1
    • 1.4.1-1
    • 1.4.3-1
    • 1.5.0-1
    • 1.6.0-1
    • 1.6.1-1
    • 1.6.2-1
    • 1.6.3-1
    • 1.6.4-1
    • 1.6.5-1
    • 1.6.8-1
    • 1.7.0-1
    • 1.7.1-1
    • 1.7.2-1
    • 1.7.3-1
    • 1.7.4-1
    • 1.7.5-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • joserfc Debian:14

    Versions
    • 1.1.0-1
    • 1.2.0-1
    • 1.2.2-1
    • 1.3.1-1
    • 1.3.2-1
    • 1.3.4-1
    • 1.4.0-1
    • 1.4.1-1
    • 1.4.3-1
    • 1.5.0-1
    • 1.6.0-1
    • 1.6.1-1
    • 1.6.2-1
    • 1.6.3-1
    • 1.6.4-1
    • 1.6.5-1
    • 1.6.8-1
    • 1.7.0-1
    • 1.7.1-1
    • 1.7.2-1
    Affected ranges
    • ECOSYSTEM: < 1.7.3-1

    Update to 1.7.3-1

  • joserfc Ubuntu:26.04:LTS

    Versions
    • 1.2.2-1
    • 1.4.0-1
    • 1.4.1-1
    • 1.4.3-1
    • 1.5.0-1
    • 1.6.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

Check your server →