Buffer overflow in Mozilla Firefox and Firefox for Android - CVE-2026-12326
Published: June 16, 2026
Vulnerability identifier: #VU134646
CSH Severity: High
CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-12326
CWE-ID: CWE-119
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to memory corruption in Firefox when parsing input. A remote attacker can supply crafted input to execute arbitrary code.
Some of these bugs showed evidence of memory corruption.
Affected software
Mozilla Firefox
Firefox for Android
Mozilla Thunderbird
Firefox for Android
Mozilla Thunderbird
How to mitigate CVE-2026-12326
Install security update from vendor's website.
Mozilla Firefox - update to 152.0
Firefox for Android - update to 152.0
Mozilla Thunderbird - update to 152.0
Firefox for Android - update to 152.0
Mozilla Thunderbird - update to 152.0
External References
- https://www.mozilla.org/en-US/security/advisories/mfsa2026-57/
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2039050
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2042718
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2042760
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2044831
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2045307
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2045398
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2045516
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2045572
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2041741
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2044433