PT-2026-21732 · Mozilla · Thunderbird+1

Published 2026-02-24 · Updated 2026-03-01 · CVE-2026-2799

Positive Technologies (AI Summary)

CVSS v2.0

10

Critical

Base vector

AV:N/AC:L/Au:N/C:C/I:C/A:C

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 148 Thunderbird versions prior to 148

Description A use-after-free issue exists in the DOM: Core & HTML component. This condition occurs when memory is accessed after it has been freed, potentially leading to crashes or arbitrary code execution.

Recommendations Update Firefox to version 148 or later. Update Thunderbird to version 148 or later.

Fix

Use After Free

Weakness Enumeration

CWE-416

Related Identifiers

BDU:2026-06191

CVE-2026-2799

OPENSUSE-SU-2026:10257-1

Affected Products

Firefox

Thunderbird

References · 72

• https://mozilla.org/en-US/security/advisories/mfsa2026-13 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-16 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-13 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-2799 · Security Note
• https://osv.dev/vulnerability/CVE-2026-2799 · Vendor Advisory
• https://mozilla.org/en-US/security/advisories/mfsa2026-16 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-2799 · Vendor Advisory
• https://wiki.astralinux.ru/astra-linux-se18-bulletin-2026-0423SE18MD · Vendor Advisory
• https://mozilla.org/en-US/security/advisories/mfsa2026-13/#CVE-2026-2799 · Vendor Advisory
• https://bdu.fstec.ru/vul/2026-06191 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-2799 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-2799 · Security Note
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-2799 · Security Note
• https://wiki.astralinux.ru/astra-linux-se47-bulletin-2026-0518SE47 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-2799 · Vendor Advisory