PT-2026-27427 · Mozilla · Firefox+1

Christian Holler + 3 · Published 2026-03-24 · Updated 2026-03-29 · CVE-2026-4729

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 149 Thunderbird versions prior to 149

Description Memory safety issues exist in Firefox 148 and Thunderbird 148. These bugs demonstrate evidence of memory corruption, and it is presumed that, with sufficient effort, they could potentially be exploited to execute arbitrary code.

Recommendations Update Firefox to version 149 or later. Update Thunderbird to version 149 or later.

Fix

RCE

Buffer Overflow

Weakness Enumeration

CWE-120

Related Identifiers

CVE-2026-4729

OPENSUSE-SU-2026:10458-1

Affected Products

Firefox

Thunderbird

References · 57

• https://osv.dev/vulnerability/openSUSE-SU-2026:10458-1 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-23 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-4729 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-4729 · Security Note
• https://mozilla.org/en-US/security/advisories/mfsa2026-20/#CVE-2026-4729 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-4729 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-4729 · Security Note
• https://mozilla.org/security/advisories/mfsa2026-20 · Vendor Advisory
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=1944033%2C1997282%2C2009213%2C2011412%2C2021925%2C2022034 · Note
• https://suse.com/security/cve/CVE-2026-4721 · Note
• https://suse.com/security/cve/CVE-2026-4705 · Note
• https://suse.com/security/cve/CVE-2026-4722 · Note
• https://suse.com/security/cve/CVE-2026-4728 · Note
• https://suse.com/security/cve/CVE-2026-4686 · Note
• https://suse.com/security/cve/CVE-2026-4688 · Note