PT-2026-27396 · Mozilla · Firefox+2

Lorenzo · Published 2026-03-24 · Updated 2026-03-24 · CVE-2026-4697

Positive Technologies · (AI Summary)

CVSS v3.1

7.5

High

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

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 149 Firefox ESR versions prior to 140.9 Thunderbird versions prior to 149 Thunderbird versions prior to 140.9

Description The Audio/Video: Web Codecs component contains incorrect boundary conditions.

Recommendations Update Firefox to version 149 or later. Update Firefox ESR to version 140.9 or later. Update Thunderbird to version 149 or later. Update Thunderbird to version 140.9 or later.

Fix

Improper Check for Exceptional Conditions

Weakness Enumeration

CWE-754

Related Identifiers

CVE-2026-4697

Affected Products

Firefox

Firefox Esr

Thunderbird

References · 6

• https://mozilla.org/security/advisories/mfsa2026-23 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-4697 · Security Note
• https://mozilla.org/security/advisories/mfsa2026-24 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-22 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-20 · Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=2020422 · Note