PT-2026-49669 · Mozilla · Firefox+1

Niklas · Published 2026-06-16 · Updated 2026-06-16 · CVE-2026-12300

Positive Technologies (AI Summary)

CVSS v3.1

5.3

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 152 Thunderbird versions prior to 152

Description A memory safety bug exists in the software, which could lead to unexpected behavior or crashes when handling memory operations.

Recommendations Update to version 152 for Firefox. Update to version 152 for Thunderbird.

Fix

Buffer Overflow

Weakness Enumeration

CWE-119

Related Identifiers

CVE-2026-12300

Affected Products

Firefox

Thunderbird

References · 4

• https://mozilla.org/security/advisories/mfsa2026-60 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-12300 · Security Note
• https://mozilla.org/security/advisories/mfsa2026-57 · Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1704114 · Note