CVE-2026-12315: Mozilla Firefox · CWE-693
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited · CVSS 9.1 Critical · patch available : patch Mozilla Firefox as a priority.
Data as of 30 Oct 2026, 20:25 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 16% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NExploitation 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 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Firefox | Affected
| Fixed in
|
AI-suggested
A fix is available and has been officially released by Mozilla. Users and administrators should upgrade to Firefox 152 or later, or Firefox ESR 140.12 or later, to remediate this vulnerability. The vendor advisories at https://www.mozilla.org/security/advisories/mfsa2026-57/ and https://www.mozilla.org/security/advisories/mfsa2026-58/ provide authoritative guidance and confirm the fix status.
Description
CVE-2026-12315 is a mitigation bypass vulnerability in the DOM security component of Mozilla Firefox. It was fixed in Firefox 152 and Firefox ESR 140.12. The vulnerability has a critical CVSS score of 9.1, indicating high impact on confidentiality and integrity without requiring user interaction or privileges. The vendor advisory confirms the fix availability in these versions.
References
- bugzilla.mozilla.org/show_bug.cgi?id=2042058 (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/mfsa2026-60/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-61/ (opens in a new tab)