CVE catalog

CVE-2026-102266

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.from_jwk is affected because PyJWK verification path used the decoded key without applying prepare

[CVE catalog]

Severity
Critical · CVSS 9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Published
Updated
Source
[NVD] · [CVE record]
EPSS
0.22% · Oct 25, 2026

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.from_jwk is affected because PyJWK verification path used the decoded key without applying prepare_key validation. This occurs when a trusted JWK Set contains an oct entry with an empty k value. As a result, an attacker signs an HMAC token with the same zero-length key accepted by PyJWT. Consequently, forged token can carry arbitrary authenticated claims. This issue is fixed in version 2.14.0.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

DistributionPackageReleaseVersionStatus
Debianpyjwtsid2.15.1-1fixed
Debianpyjwtforky2.15.1-1fixed
Debianpyjwttrixie2.10.1-2+deb13u1vulnerable
Debianpyjwttrixie-security2.10.1-2+deb13u1vulnerable
Debianpyjwtbookworm2.6.0-1+deb12u1not affected
Debianpyjwtbookworm-security2.6.0-1+deb12u1not affected
PyPIpyjwtNot reported2.14.0fixed
PyPIpyjwtNot reported2.14.0fixed
CpepyjwtNot reportedNot reportedunknown
Ubuntupyjwtnoble2.7.0-1ubuntu0.3fixed
Ubuntupython3-jwtnoble2.7.0-1ubuntu0.3fixed
Ubuntupyjwt26.102.10.1-4ubuntu1vulnerable
Ubuntupyjwt26.102.12.1-1vulnerable
Ubuntupyjwt26.102.13.0-1vulnerable
Ubuntupyjwt26.102.13.0-1ubuntu1fixed
Ubuntupyjwt26.042.10.1-2vulnerable
Ubuntupyjwt26.042.10.1-3vulnerable
Ubuntupyjwt26.042.10.1-3build1vulnerable
Ubuntupyjwt26.042.10.1-4vulnerable
Ubuntupyjwt26.042.10.1-4ubuntu1vulnerable
Ubuntupyjwt26.042.10.1-4ubuntu1.1vulnerable
Ubuntupyjwt26.042.10.1-4ubuntu1.2fixed
Ubuntupyjwt26.102.10.1-4ubuntu1vulnerable
Ubuntupyjwt26.102.12.1-1vulnerable
Ubuntupyjwt26.102.13.0-1vulnerable
Ubuntupyjwt26.102.13.0-1ubuntu1fixed
Ubuntupyjwtpro1.7.0-2vulnerable
Ubuntupyjwtpro1.7.1-1vulnerable
Ubuntupyjwtpro1.7.1-2ubuntu1vulnerable
Ubuntupyjwtpro1.7.1-2ubuntu2vulnerable
Ubuntupyjwtpro1.7.1-2ubuntu2.1vulnerable
Ubuntupyjwtpro1.7.1-2ubuntu2.1+esm1vulnerable
Ubuntupyjwtpro1.7.1-2ubuntu2.1+esm2vulnerable
Ubuntupyjwtpro1.7.1-2ubuntu2.1+esm3fixed
Ubuntupyjwt22.041.7.1-2ubuntu2vulnerable
Ubuntupyjwt22.042.1.0-1vulnerable
Ubuntupyjwt22.042.3.0-1vulnerable
Ubuntupyjwt22.042.3.0-1ubuntu0.1vulnerable
Ubuntupyjwt22.042.3.0-1ubuntu0.2vulnerable
Ubuntupyjwt22.042.3.0-1ubuntu0.3vulnerable
Ubuntupyjwt22.042.3.0-1ubuntu0.4vulnerable
Ubuntupyjwt22.042.3.0-1ubuntu0.5fixed
Ubuntupyjwt24.042.7.0-1vulnerable
Ubuntupyjwt24.042.7.0-1ubuntu0.1vulnerable
Ubuntupyjwt24.042.7.0-1ubuntu0.2vulnerable
Ubuntupyjwt24.042.7.0-1ubuntu0.3fixed
Ubuntupyjwt26.042.10.1-2vulnerable
Ubuntupyjwt26.042.10.1-3vulnerable
Ubuntupyjwt26.042.10.1-3build1vulnerable
Ubuntupyjwt26.042.10.1-4vulnerable
Ubuntupyjwt26.042.10.1-4ubuntu1vulnerable
Ubuntupyjwt26.042.10.1-4ubuntu1.1vulnerable
Ubuntupyjwt26.042.10.1-4ubuntu1.2fixed

Fixed-version evidence

DistributionPackageTypeReleaseFixed versionUrgencyOriginBugs
Debianpyjwtsourcesid2.14.0-1not yet assignedNot reportedNot reported
Debianpyjwtsourceforky2.14.0-1not yet assignedNot reportedNot reported
Debianpyjwtsourcetrixie(unfixed)not yet assignedNot reportedNot reported
DebianpyjwtsourcebookwormNot affectedunimportantNot reportedNot reported
PyPIpyjwtPyPINot reported2.14.0Not reportedGHSA-9J54-FG26-WV3RNot reported
PyPIpyjwtPyPINot reported2.14.0Not reportedPYSEC-2026-4143Not reported
Ubuntupyjwtdebnoble2.7.0-1ubuntu0.3Not reportedNot reportedNot reported
Ubuntupython3-jwtdebnoble2.7.0-1ubuntu0.3Not reportedNot reportedNot reported
Ubuntupyjwtdeb26.102.13.0-1ubuntu1Not reportedUBUNTU-CVE-2026-102266Not reported
Ubuntupyjwtdeb26.042.10.1-4ubuntu1.2Not reportedUBUNTU-CVE-2026-102266Not reported
Ubuntupyjwtdeb26.102.13.0-1ubuntu1Not reportedUSN-8916-2Not reported
Ubuntupyjwtdebpro1.7.1-2ubuntu2.1+esm3Not reportedUSN-8916-1Not reported
Ubuntupyjwtdeb22.042.3.0-1ubuntu0.5Not reportedUSN-8916-1Not reported
Ubuntupyjwtdeb24.042.7.0-1ubuntu0.3Not reportedUSN-8916-1Not reported
Ubuntupyjwtdeb26.042.10.1-4ubuntu1.2Not reportedUSN-8916-1Not reported

OpenFactory catalog packages

[Debian 13 (Trixie)]

  • [python3-jwt]Affected

    Source package: [pyjwt]

    Details (4)

    • 2.10.1-2+deb13u1 · all · trixie

      Affected

      nvd · pyjwt · debian · 13

    • 2.10.1-2+deb13u1 · all · trixie

      Affected

      nvd · pyjwt · debian · 13

    • 2.10.1-2+deb13u1 · all · trixie-security

      Affected

      nvd · pyjwt · debian · 13

    • 2.10.1-2+deb13u1 · all · trixie-security

      Affected

      nvd · pyjwt · debian · 13

  • [python-jwt-doc]Affected

    Source package: [pyjwt]

    Details (4)

    • 2.10.1-2+deb13u1 · all · trixie

      Affected

      nvd · pyjwt · debian · 13

    • 2.10.1-2+deb13u1 · all · trixie

      Affected

      nvd · pyjwt · debian · 13

    • 2.10.1-2+deb13u1 · all · trixie-security

      Affected

      nvd · pyjwt · debian · 13

    • 2.10.1-2+deb13u1 · all · trixie-security

      Affected

      nvd · pyjwt · debian · 13

[Debian 12 (Bookworm)]

  • [python3-jwt]Not affected

    Source package: [pyjwt]

    Details (4)

    • 2.6.0-1+deb12u1 · all · bookworm

      Not affected

      nvd · pyjwt · debian · bookworm

    • 2.6.0-1+deb12u1 · all · bookworm

      Not affected

      nvd · pyjwt · debian · bookworm

    • 2.6.0-1+deb12u1 · all · bookworm-security

      Not affected

      nvd · pyjwt · debian · bookworm

    • 2.6.0-1+deb12u1 · all · bookworm-security

      Not affected

      nvd · pyjwt · debian · bookworm

Observed:

References

[Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]