Bug 2467279 (CVE-2026-42009)

Summary: CVE-2026-42009 gnutls: gnutls: Denial of Service via DTLS packet reordering vulnerability
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: kshier, rhel-process-autobot, stcannon, teagle, watson-tool-maintainers, yguenane
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in gnutls. A remote attacker could exploit an issue in the Datagram Transport Layer Security (DTLS) packet reordering logic. The comparator function, responsible for ordering DTLS packets by sequence numbers, did not correctly handle packets with duplicate sequence numbers. This could lead to unstable packet ordering or undefined behavior, resulting in a denial of service.
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-05-06 16:35:48 UTC
The comparator function used for ordering DTLS packets by sequence numbers did not follow qsort comparator contracts in case of packets with duplicate sequence numbers, which could lead to unstable ordering or undefined behaviour. Return 0 in such cases makes the sorting stable. Additionally, discard packets with same sequence numbers and differing handshake type, so that they don't end up being sorted in the first place.

Comment 2 errata-xmlrpc 2026-05-26 06:15:27 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:20611 https://access.redhat.com/errata/RHSA-2026:20611

Comment 3 errata-xmlrpc 2026-05-26 06:18:00 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:20613 https://access.redhat.com/errata/RHSA-2026:20613

Comment 4 errata-xmlrpc 2026-05-26 06:20:05 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:20612 https://access.redhat.com/errata/RHSA-2026:20612

Comment 10 errata-xmlrpc 2026-06-16 16:39:22 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:26409 https://access.redhat.com/errata/RHSA-2026:26409

Comment 12 errata-xmlrpc 2026-06-25 18:07:33 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:30004 https://access.redhat.com/errata/RHSA-2026:30004

Comment 13 errata-xmlrpc 2026-06-29 02:30:12 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.8 Telecommunications Update Service

Via RHSA-2026:30850 https://access.redhat.com/errata/RHSA-2026:30850

Comment 14 errata-xmlrpc 2026-06-29 02:48:28 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On

Via RHSA-2026:30849 https://access.redhat.com/errata/RHSA-2026:30849

Comment 15 errata-xmlrpc 2026-06-29 09:47:25 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

Via RHSA-2026:32962 https://access.redhat.com/errata/RHSA-2026:32962

Comment 16 errata-xmlrpc 2026-06-29 15:07:28 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

Via RHSA-2026:33125 https://access.redhat.com/errata/RHSA-2026:33125

Comment 17 errata-xmlrpc 2026-06-30 15:49:26 UTC
This issue has been addressed in the following products:

  Red Hat OpenShift Container Platform 4.22

Via RHSA-2026:29794 https://access.redhat.com/errata/RHSA-2026:29794

Comment 18 errata-xmlrpc 2026-07-01 18:45:58 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2026:34372 https://access.redhat.com/errata/RHSA-2026:34372

Comment 19 errata-xmlrpc 2026-07-07 12:38:50 UTC
This issue has been addressed in the following products:

  Red Hat OpenShift Container Platform 4.20

Via RHSA-2026:34788 https://access.redhat.com/errata/RHSA-2026:34788

Comment 20 errata-xmlrpc 2026-07-07 14:22:25 UTC
This issue has been addressed in the following products:

  Red Hat OpenShift Container Platform 4.21

Via RHSA-2026:34764 https://access.redhat.com/errata/RHSA-2026:34764