PT-2026-27426 · Mozilla · Thunderbird+1

Aswinkumar Gokulakannan · Published 2026-03-24 · Updated 2026-03-29 · CVE-2026-4728

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

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

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

Description A spoofing issue exists in the Privacy: Anti-Tracking component.

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

Fix

Authentication Bypass by Spoofing

Weakness Enumeration

CWE-290

Related Identifiers

CVE-2026-4728

OPENSUSE-SU-2026:10458-1

Affected Products

Firefox

Thunderbird

References · 56

• https://mozilla.org/security/advisories/mfsa2026-23 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-4728 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-4728 · Security Note
• https://ubuntu.com/security/CVE-2026-4728 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-4728 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2026:10458-1 · Vendor Advisory
• https://mozilla.org/en-US/security/advisories/mfsa2026-20/#CVE-2026-4728 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-20 · Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=2013179 · Note
• https://suse.com/security/cve/CVE-2025-59375 · Note
• https://suse.com/security/cve/CVE-2026-4688 · Note
• https://suse.com/security/cve/CVE-2026-4710 · Note
• https://suse.com/security/cve/CVE-2026-4692 · Note
• https://suse.com/security/cve/CVE-2026-4715 · Note
• https://suse.com/security/cve/CVE-2026-4691 · Note