Bug 2543164 (CVE-2026-100803) - CVE-2026-100803 firefox: thunderbird: Same-origin policy bypass in the WebExtensions component
Summary: CVE-2026-100803 firefox: thunderbird: Same-origin policy bypass in the WebExt...
Keywords:
Status: NEW
Alias: CVE-2026-100803
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-29 13:09 UTC by OSIDB Bzimport
Modified: 2026-10-16 08:41 UTC (History)
5 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-2026:76761 0 None None None 2026-10-08 06:35:34 UTC
Red Hat Product Errata RHSA-2026:76764 0 None None None 2026-10-06 20:19:10 UTC
Red Hat Product Errata RHSA-2026:76850 0 None None None 2026-10-06 19:19:07 UTC
Red Hat Product Errata RHSA-2026:80674 0 None None None 2026-10-12 09:21:23 UTC
Red Hat Product Errata RHSA-2026:80694 0 None None None 2026-10-12 10:29:12 UTC

Description OSIDB Bzimport 2026-09-29 13:09:31 UTC 
Same-origin policy bypass in the WebExtensions component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
Comment 1 Jon Orris 2026-10-06 19:19:07 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:76850 https://access.redhat.com/errata/RHSA-2026:76850
Comment 2 Jon Orris 2026-10-06 20:19:09 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:76764 https://access.redhat.com/errata/RHSA-2026:76764
Comment 3 Jon Orris 2026-10-08 06:35:33 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:76761 https://access.redhat.com/errata/RHSA-2026:76761
Comment 4 Jon Orris 2026-10-12 09:21:22 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:80674 https://access.redhat.com/errata/RHSA-2026:80674
Comment 5 Jon Orris 2026-10-12 10:29:11 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:80694 https://access.redhat.com/errata/RHSA-2026:80694
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