CVE-2026-12306

Memory safety bug fixed in Firefox 152

CVSS 5.3 MEDIUMEPSS 0.3%CWE-119

Vexday Risk Score

13Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 5.3EPSS 0.3%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

16 Jun 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected products

Mozilla · Firefox Mozilla · Thunderbird

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2037323 https://www.mozilla.org/security/advisories/mfsa2026-57/https://www.mozilla.org/security/advisories/mfsa2026-58/https://www.mozilla.org/security/advisories/mfsa2026-60/https://www.mozilla.org/security/advisories/mfsa2026-61/