PT-2026-30826 · Mozilla · Thunderbird+1

Brian Grinstead + 2 · CVE-2026-5735 · Published 2026-04-07 · Updated 2026-07-25

Positive Technologies (AI Summary)

CVSS v2.0

10

High

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 149.0.2 Thunderbird versions prior to 149.0.2

Description Memory safety bugs exist in Firefox 149.0.1 and Thunderbird 149.0.1. These bugs demonstrate evidence of memory corruption, and it is presumed that, with sufficient effort, they could be exploited to execute arbitrary code. The vulnerability involves writing beyond buffer boundaries.

Recommendations Update Firefox to version 149.0.2 or later. Update Thunderbird to version 149.0.2 or later.

Fix

DoS

Memory Corruption

Out of bounds Read

Weakness Enumeration

CWE-787

CWE-125

Related Identifiers

BDU:2026-04823

CVE-2026-5735

OPENSUSE-SU-2026:10511-1

OPENSUSE-SU-2026:11373-1

Affected Products

Firefox

Thunderbird

References · 250

• https://cve.org/CVERecord?id=CVE-2026-5735 · Security Note
• https://mozilla.org/en-US/security/advisories/mfsa2026-25 · Vendor Advisory
• https://mozilla.org/en-US/security/advisories/mfsa2026-25/#CVE-2026-5735 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-5735 · Security Note
• https://bdu.fstec.ru/vul/2026-04823 · Security Note
• https://mozilla.org/en-US/security/advisories/mfsa2026-28 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-5735 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2026:11373-1 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-25 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-28 · Vendor Advisory
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-5735 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-5735 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2026:10511-1 · Vendor Advisory
• https://suse.com/security/cve/CVE-2025-5271 · Note
• https://suse.com/security/cve/CVE-2025-11716 · Note