Bug 2455897 (CVE-2026-5734)

Summary:	CVE-2026-5734 thunderbird: firefox: Memory safety bugs fixed in Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	gotiwari, jgrulich, jhorak, mvyas, tpopela
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: Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. 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.	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 2026-04-07 13:01:25 UTC

Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. 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 < 149.0.2 and Firefox ESR < 140.9.1.

Comment 1 errata-xmlrpc 2026-04-13 02:19:46 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:7672 https://access.redhat.com/errata/RHSA-2026:7672

Comment 2 errata-xmlrpc 2026-04-13 02:23:50 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:7671 https://access.redhat.com/errata/RHSA-2026:7671

Comment 3 errata-xmlrpc 2026-04-14 11:32:48 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:8052 https://access.redhat.com/errata/RHSA-2026:8052

Comment 4 errata-xmlrpc 2026-04-16 12:51:32 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:8459 https://access.redhat.com/errata/RHSA-2026:8459