PT-2026-49676 · Mozilla · Firefox+1

Atsushi Sada · Published 2026-06-16 · Updated 2026-06-16 · CVE-2026-12307

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 Firefox ESR versions prior to 140.12 Thunderbird versions prior to 152 Thunderbird versions prior to 140.12

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

Recommendations Update Firefox to version 152. Update Firefox ESR to version 140.12. Update Thunderbird to version 152. Update Thunderbird to version 140.12.

Fix

Buffer Overflow

Weakness Enumeration

CWE-119

Related Identifiers

CVE-2026-12307

Affected Products

Firefox

Thunderbird

References · 6

• https://mozilla.org/security/advisories/mfsa2026-60 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-57 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-61 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-12307 · Security Note
• https://mozilla.org/security/advisories/mfsa2026-58 · Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=2038133 · Note