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CVE-2026-48524

CVE-2026-48524 · PyJWT: PyJWKClient unbounded JWKS endpoint requests via attacker-controlled kid values (DoS)

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

PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient.get_signing_key() forces a fresh HTTP request to the JWKS endpoint for every JWT with an unknown kid value, with no rate limiting. Since kid comes from the unverified token header, an attacker can trigger unlimited outbound requests. The vulnerability surfaces only when a JWKS fetch fails; an attacker can attempt to provoke that with sustained unknown-kid traffic, but the outcome depends on upstream JWKS-endpoint behavior (rate limiting, transient errors) which is beyond the attacker's control. This vulnerability is fixed in 2.13.0.

CVSS 3.7 · Low · EPSS 0.3% · Fix available

Published
Updated

Stack: system · python

Affected products and versions

  • pyjwt

    Versions
    • < 2.13.0: Affected

    No fix published

  • pyjwt Debian:12

    Versions
    • 2.10.1-1
    • 2.10.1-2
    • 2.10.1-3
    • 2.10.1-4
    • 2.11.0-2
    • 2.12.1-1
    • 2.13.0-1
    • 2.14.0-1
    • 2.15.0-1
    • 2.15.1-1
    • 2.6.0-1
    • 2.6.0-1+deb12u1
    • 2.7.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pyjwt Debian:13

    Versions
    • 2.10.1-2
    • 2.10.1-2+deb13u1
    • 2.10.1-3
    • 2.10.1-4
    • 2.11.0-2
    • 2.12.1-1
    • 2.13.0-1
    • 2.14.0-1
    • 2.15.0-1
    • 2.15.1-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pyjwt Debian:14

    Versions
    • 2.10.1-2
    • 2.10.1-3
    • 2.10.1-4
    • 2.11.0-2
    • 2.12.1-1
    Affected ranges
    • ECOSYSTEM: < 2.13.0-1

    Update to 2.13.0-1

  • pyjwt PyPI

    Versions
    • 2.0.0
    • 2.0.1
    • 2.1.0
    • 2.10.0
    • 2.10.1
    • 2.11.0
    • 2.12.0
    • 2.12.1
    • 2.2.0
    • 2.3.0
    • 2.4.0
    • 2.5.0
    • 2.6.0
    • 2.7.0
    • 2.8.0
    • 2.9.0
    Affected ranges
    • ECOSYSTEM: ≥ 2.0.0, < 2.13.0

    Update to 2.13.0

  • pyjwt PyPI

    Versions
    • 0.1.1
    • 0.1.2
    • 0.1.3
    • 0.1.4
    • 0.1.5
    • 0.1.6
    • 0.1.7
    • 0.1.8
    • 0.1.9
    • 0.2.0
    • 0.2.1
    • 0.2.3
    • 0.3.0
    • 0.3.1
    • 0.3.2
    • 0.4.0
    • 0.4.1
    • 0.4.2
    • 0.4.3
    • 1.0.0
    • 1.0.1
    • 1.1.0
    • 1.3.0
    • 1.4.0
    • 1.4.1
    • 1.4.2
    • 1.5.0
    • 1.5.1
    • 1.5.2
    • 1.5.3
    • 1.6.0
    • 1.6.1
    • 1.6.3
    • 1.6.4
    • 1.7.0
    • 1.7.1
    • 2.0.0
    • 2.0.0a1
    • 2.0.0a2
    • 2.0.1
    • 2.1.0
    • 2.10.0
    • 2.10.1
    • 2.11.0
    • 2.12.0
    • 2.12.1
    • 2.2.0
    • 2.3.0
    • 2.4.0
    • 2.5.0
    • 2.6.0
    • 2.7.0
    • 2.8.0
    • 2.9.0
    Affected ranges
    • ECOSYSTEM: < 2.13.0

    Update to 2.13.0

  • pyjwt Ubuntu:24.04:LTS

    Versions
    • 2.7.0-1
    • 2.7.0-1ubuntu0.1
    Affected ranges
    • ECOSYSTEM: < 2.7.0-1ubuntu0.2

    Update to 2.7.0-1ubuntu0.2

  • pyjwt Ubuntu:25.10

    Versions
    • 2.10.1-2
    • 2.10.1-2ubuntu0.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pyjwt Ubuntu:26.04:LTS

    Versions
    • 2.10.1-2
    • 2.10.1-3
    • 2.10.1-3build1
    • 2.10.1-4
    • 2.10.1-4ubuntu1
    Affected ranges
    • ECOSYSTEM: < 2.10.1-4ubuntu1.1

    Update to 2.10.1-4ubuntu1.1

Original sources

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