CVE-2026-12302: Mozilla Firefox · CWE-693
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited · CVSS 6.5 Medium · patch available : update Mozilla Firefox when convenient.
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:L/I:L/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
Mozilla has released official fixes for this vulnerability in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37. Users and administrators should update affected Firefox and Firefox ESR installations to these versions or later to remediate this issue. No additional mitigation steps are indicated by the vendor advisories.
Description
CVE-2026-12302 is a mitigation bypass vulnerability in the DOM security component of Mozilla Firefox. It affects Firefox versions prior to 152, Firefox ESR versions up to 140.11, and ESR versions up to 115.36. The vulnerability was fixed in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37. The CVSS 3.1 base score is 6.5, indicating a medium severity. This issue allows bypassing security mitigations within the DOM, potentially impacting confidentiality and integrity. No known exploits in the wild have been reported. Mozilla has released official fixes in the stated versions.
References
- bugzilla.mozilla.org/show_bug.cgi?id=2034489 (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)