CVE-2026-12328: Mozilla Firefox · Buffer Overflow
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited · CVSS 8.1 High.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Firefox | Affected
| Fixed in– |
AI-suggested
Mozilla has released official fixes for these vulnerabilities in Firefox 152, Firefox ESR 115.37, Firefox ESR 140.12, Thunderbird 152, and Thunderbird ESR 140.12. Users and administrators should upgrade to these fixed versions to remediate the vulnerabilities. Patch status is confirmed by the vendor advisories. No additional mitigation beyond applying these updates is indicated.
Description
Memory safety bugs present in Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird ESR 140.11, Firefox 151 and Thunderbird 151. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.
References
- bugzilla.mozilla.org/buglist.cgi?bug_id=2029402%2C2038477%2C2039726%2C2041373%2C2042268%2C2042451%2C2042782%2C2042858%2C2042929%2C2042965%2C2043213 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-57/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-58/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-59/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-60/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-61/ (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-12328 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2489218 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12328.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:38506 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36100 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:38751 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:27733 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:30846 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:27717 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:33445 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36102 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:39428 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37210 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:39141 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36103 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:39142 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36101 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:39706 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:39011 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:38753 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37391 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:38750 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:27734 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:29940 (opens in a new tab)