Bug 2451106 (CVE-2026-33999)

Summary: CVE-2026-33999 xorg: xwayland: X.Org X server: Denial of Service via integer underflow in XKB compatibility map handling
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: rhel-process-autobot, security-response-team, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of service (DoS) or other severe impacts.
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:
Bug Depends On: 2476954, 2476957, 2476956    
Bug Blocks:    

Description OSIDB Bzimport 2026-03-25 06:29:42 UTC
Integer Underflow (Wraparound) vulnerability in the XKB compatibility map handling of the X.Org X server. The issue occurs in XkbSetCompatMap() when a previously truncated “compat” buffer leaves unused space that is later reused without correctly updating the count of valid entries. This can cause internal size/index calculations to become inconsistent and potentially underflow, resulting in a buffer read overrun when subsequent XKB requests are processed. An attacker with access to the X11 server (local or via remote X11 forwarding/SSH tunneling) can trigger the flaw without user interaction, leading to memory-safety violations and potentially a crash or more severe impact depending on how Xorg/Xwayland is deployed.

Comment 4 errata-xmlrpc 2026-04-27 08:29:51 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:10739 https://access.redhat.com/errata/RHSA-2026:10739

Comment 5 errata-xmlrpc 2026-04-28 11:20:59 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:11352 https://access.redhat.com/errata/RHSA-2026:11352

Comment 6 errata-xmlrpc 2026-04-28 14:53:16 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:11369 https://access.redhat.com/errata/RHSA-2026:11369

Comment 7 errata-xmlrpc 2026-04-28 17:58:04 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:11388 https://access.redhat.com/errata/RHSA-2026:11388

Comment 8 errata-xmlrpc 2026-04-29 12:01:21 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:11656 https://access.redhat.com/errata/RHSA-2026:11656

Comment 9 errata-xmlrpc 2026-04-29 13:07:51 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:11692 https://access.redhat.com/errata/RHSA-2026:11692

Comment 10 errata-xmlrpc 2026-05-04 12:29:09 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:13414 https://access.redhat.com/errata/RHSA-2026:13414

Comment 11 errata-xmlrpc 2026-05-19 16:05:07 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:19125 https://access.redhat.com/errata/RHSA-2026:19125

Comment 12 errata-xmlrpc 2026-05-19 21:36:57 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:19342 https://access.redhat.com/errata/RHSA-2026:19342

Comment 13 errata-xmlrpc 2026-05-19 21:37:04 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:19343 https://access.redhat.com/errata/RHSA-2026:19343

Comment 14 errata-xmlrpc 2026-05-19 21:41:45 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:19344 https://access.redhat.com/errata/RHSA-2026:19344

Comment 15 errata-xmlrpc 2026-05-26 01:56:59 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

Via RHSA-2026:20562 https://access.redhat.com/errata/RHSA-2026:20562

Comment 16 errata-xmlrpc 2026-05-26 02:48:47 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:20557 https://access.redhat.com/errata/RHSA-2026:20557

Comment 17 errata-xmlrpc 2026-05-26 03:03:48 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:20547 https://access.redhat.com/errata/RHSA-2026:20547

Comment 18 errata-xmlrpc 2026-05-26 03:04:17 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Extended Update Support

Via RHSA-2026:20560 https://access.redhat.com/errata/RHSA-2026:20560

Comment 19 errata-xmlrpc 2026-05-26 03:18:12 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:20563 https://access.redhat.com/errata/RHSA-2026:20563

Comment 20 errata-xmlrpc 2026-05-26 03:43:20 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:20561 https://access.redhat.com/errata/RHSA-2026:20561

Comment 21 errata-xmlrpc 2026-05-26 03:50:32 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:20558 https://access.redhat.com/errata/RHSA-2026:20558

Comment 22 errata-xmlrpc 2026-05-26 04:00:37 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Extended Update Support

Via RHSA-2026:20575 https://access.redhat.com/errata/RHSA-2026:20575

Comment 23 errata-xmlrpc 2026-05-26 04:31:01 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2026:20590 https://access.redhat.com/errata/RHSA-2026:20590

Comment 24 errata-xmlrpc 2026-05-26 04:55:28 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:20576 https://access.redhat.com/errata/RHSA-2026:20576

Comment 25 errata-xmlrpc 2026-05-26 04:58:57 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Extended Update Support

Via RHSA-2026:20555 https://access.redhat.com/errata/RHSA-2026:20555

Comment 26 errata-xmlrpc 2026-05-28 07:49:11 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

Via RHSA-2026:21699 https://access.redhat.com/errata/RHSA-2026:21699

Comment 27 errata-xmlrpc 2026-05-28 09:33:22 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-2026:21712 https://access.redhat.com/errata/RHSA-2026:21712

Comment 28 errata-xmlrpc 2026-05-28 09:37:50 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-2026:21715 https://access.redhat.com/errata/RHSA-2026:21715

Comment 29 errata-xmlrpc 2026-05-28 09:44:05 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 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.6 Telecommunications Update Service

Via RHSA-2026:21716 https://access.redhat.com/errata/RHSA-2026:21716

Comment 30 errata-xmlrpc 2026-05-28 09:55:36 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 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.6 Telecommunications Update Service

Via RHSA-2026:21718 https://access.redhat.com/errata/RHSA-2026:21718

Comment 31 errata-xmlrpc 2026-05-28 11:38:16 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

Via RHSA-2026:21741 https://access.redhat.com/errata/RHSA-2026:21741

Comment 32 errata-xmlrpc 2026-05-28 12:02:32 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-2026:21742 https://access.redhat.com/errata/RHSA-2026:21742

Comment 33 errata-xmlrpc 2026-06-02 08:16:47 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:22424 https://access.redhat.com/errata/RHSA-2026:22424

Comment 34 errata-xmlrpc 2026-06-02 16:05:12 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2026:22456 https://access.redhat.com/errata/RHSA-2026:22456

Comment 35 errata-xmlrpc 2026-06-04 11:12:51 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-2026:23254 https://access.redhat.com/errata/RHSA-2026:23254

Comment 36 errata-xmlrpc 2026-06-04 11:24:25 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-2026:23255 https://access.redhat.com/errata/RHSA-2026:23255

Comment 37 errata-xmlrpc 2026-06-04 22:07:43 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6 Extended Lifecycle Support  - EXTENSION

Via RHSA-2026:23496 https://access.redhat.com/errata/RHSA-2026:23496

Comment 38 errata-xmlrpc 2026-06-08 02:03:50 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-2026:24341 https://access.redhat.com/errata/RHSA-2026:24341