Bug 2479861 (CVE-2026-8959) - CVE-2026-8959 firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component
Summary: CVE-2026-8959 firefox: thunderbird: Sandbox escape due to incorrect boundary ...
Keywords:
Status: NEW
Alias: CVE-2026-8959
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-05-19 14:02 UTC by OSIDB Bzimport
Modified: 2026-06-17 10:25 UTC (History)
7 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-2026:21381 0 None None None 2026-05-27 16:07:21 UTC
Red Hat Product Errata RHSA-2026:22325 0 None None None 2026-06-01 15:28:17 UTC
Red Hat Product Errata RHSA-2026:22643 0 None None None 2026-06-03 00:49:18 UTC
Red Hat Product Errata RHSA-2026:26174 0 None None None 2026-06-16 06:06:37 UTC
Red Hat Product Errata RHSA-2026:26268 0 None None None 2026-06-16 12:16:55 UTC
Red Hat Product Errata RHSA-2026:26269 0 None None None 2026-06-16 11:59:02 UTC
Red Hat Product Errata RHSA-2026:26270 0 None None None 2026-06-16 11:59:25 UTC
Red Hat Product Errata RHSA-2026:26521 0 None None None 2026-06-17 08:02:35 UTC
Red Hat Product Errata RHSA-2026:26536 0 None None None 2026-06-17 10:01:01 UTC
Red Hat Product Errata RHSA-2026:26539 0 None None None 2026-06-17 10:25:12 UTC

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
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