Bug 2450711 (CVE-2026-4721) - CVE-2026-4721 firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149
Summary: CVE-2026-4721 firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 1...
Keywords:
Status: NEW
Alias: CVE-2026-4721
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-03-24 13:01 UTC by OSIDB Bzimport
Modified: 2026-03-26 11:33 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-2026:5930 0 None None None 2026-03-26 11:31:37 UTC
Red Hat Product Errata RHSA-2026:5931 0 None None None 2026-03-26 11:21:55 UTC
Red Hat Product Errata RHSA-2026:5932 0 None None None 2026-03-26 11:33:13 UTC

Description OSIDB Bzimport 2026-03-24 13:01:46 UTC 
Memory safety bugs present in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9.
Comment 1 errata-xmlrpc 2026-03-26 11:21:54 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:5931 https://access.redhat.com/errata/RHSA-2026:5931
Comment 2 errata-xmlrpc 2026-03-26 11:31:36 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:5930 https://access.redhat.com/errata/RHSA-2026:5930
Comment 3 errata-xmlrpc 2026-03-26 11:33:11 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:5932 https://access.redhat.com/errata/RHSA-2026:5932
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