Bug 2479861 (CVE-2026-8959)

Summary:	CVE-2026-8959 firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	gotiwari, jgrulich, jhorak, mvyas, rhel-process-autobot, tpopela, 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 Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue: Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component	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 2026-05-19 14:02:53 UTC

Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 151 and Firefox ESR 140.11.

Comment 4 errata-xmlrpc 2026-05-27 16:07:20 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:21381 https://access.redhat.com/errata/RHSA-2026:21381

Comment 5 errata-xmlrpc 2026-06-01 15:28:15 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:22325 https://access.redhat.com/errata/RHSA-2026:22325

Comment 6 errata-xmlrpc 2026-06-03 00:49:17 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:22643 https://access.redhat.com/errata/RHSA-2026:22643

Comment 8 errata-xmlrpc 2026-06-16 06:06:36 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

Via RHSA-2026:26174 https://access.redhat.com/errata/RHSA-2026:26174

Comment 9 errata-xmlrpc 2026-06-16 11:59:00 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:26269 https://access.redhat.com/errata/RHSA-2026:26269

Comment 10 errata-xmlrpc 2026-06-16 11:59:24 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-2026:26270 https://access.redhat.com/errata/RHSA-2026:26270

Comment 11 errata-xmlrpc 2026-06-16 12:16:54 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-2026:26268 https://access.redhat.com/errata/RHSA-2026:26268

Comment 12 errata-xmlrpc 2026-06-17 08:02:34 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:26521 https://access.redhat.com/errata/RHSA-2026:26521

Comment 13 errata-xmlrpc 2026-06-17 10:01:00 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-2026:26536 https://access.redhat.com/errata/RHSA-2026:26536

Comment 14 errata-xmlrpc 2026-06-17 10:25:12 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:26539 https://access.redhat.com/errata/RHSA-2026:26539