Bug 2542687 (CVE-2026-102271) - CVE-2026-102271 pyjwt: PyJWT: Authentication bypass via acceptance of DER public keys as HMAC secrets
Summary: CVE-2026-102271 pyjwt: PyJWT: Authentication bypass via acceptance of DER pub...
Keywords:
Status: NEW
Alias: CVE-2026-102271
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-28 20:46 UTC by OSIDB Bzimport
Modified: 2026-11-11 12:04 UTC (History)
115 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2026:87004 0 None None None 2026-10-21 13:53:13 UTC
Red Hat Product Errata RHSA-2026:94500 0 None None None 2026-11-03 12:40:41 UTC
Red Hat Product Errata RHSA-2026:94501 0 None None None 2026-11-03 11:52:19 UTC
Red Hat Product Errata RHSA-2026:94523 0 None None None 2026-11-03 13:34:33 UTC
Red Hat Product Errata RHSA-2026:94557 0 None None None 2026-11-03 14:28:20 UTC
Red Hat Product Errata RHSA-2026:94634 0 None None None 2026-11-03 18:54:45 UTC
Red Hat Product Errata RHSA-2026:95012 0 None None None 2026-11-04 06:40:47 UTC
Red Hat Product Errata RHSA-2026:98503 0 None None None 2026-11-11 12:04:36 UTC
Red Hat Product Errata RHSA-2026:98612 0 None None None 2026-11-11 11:35:20 UTC

Description OSIDB Bzimport 2026-09-28 20:46:14 UTC 
PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because asymmetric-key guard relies on textual markers that are absent from DER encoding. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a DER public key as the shared verification key. As a result, PyJWT uses public DER bytes as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0.
Comment 2 Jon Orris 2026-10-21 13:53:07 UTC 
This issue has been addressed in the following products:

  Red Hat Ansible Automation Platform 2.6 for RHEL 9
  Red Hat Ansible Automation Platform 2.6 for RHEL 10

Via RHSA-2026:87004 https://access.redhat.com/errata/RHSA-2026:87004
Comment 5 Jon Orris 2026-11-03 11:52:13 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:94501 https://access.redhat.com/errata/RHSA-2026:94501
Comment 6 Jon Orris 2026-11-03 12:40:35 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:94500 https://access.redhat.com/errata/RHSA-2026:94500
Comment 7 Jon Orris 2026-11-03 13:34:27 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:94523 https://access.redhat.com/errata/RHSA-2026:94523
Comment 8 Jon Orris 2026-11-03 14:28:14 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

Via RHSA-2026:94557 https://access.redhat.com/errata/RHSA-2026:94557
Comment 9 Jon Orris 2026-11-03 18:54:39 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:94634 https://access.redhat.com/errata/RHSA-2026:94634
Comment 10 Jon Orris 2026-11-04 06:40:41 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:95012 https://access.redhat.com/errata/RHSA-2026:95012
Comment 12 errata-xmlrpc 2026-11-11 11:35:09 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:98612 https://access.redhat.com/errata/RHSA-2026:98612
Comment 13 errata-xmlrpc 2026-11-11 12:04:28 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:98503 https://access.redhat.com/errata/RHSA-2026:98503
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