CVE-2026-12299: Vulnerability in Mozilla Firefox
JIT miscompilation in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37.
AI Analysis
Technical Summary
CVE-2026-12299 is a vulnerability in Mozilla Firefox caused by JIT miscompilation within the DOM: Core & HTML component. This bug was resolved in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37. The Mozilla advisories classify the impact as high and include references to the bug report (Bug 2043139). The vulnerability is part of a broader set of security fixes released simultaneously, addressing multiple high-impact issues. No known exploits in the wild have been reported. The vendor advisories confirm that the vulnerability is fixed in the specified versions.
Potential Impact
The vulnerability involves just-in-time (JIT) miscompilation in the DOM, which can lead to incorrect code execution within the browser environment. This can undermine browser security and potentially allow attackers to execute unintended code paths. The impact is rated high by Mozilla. There are no reports of active exploitation in the wild. The fix eliminates the vulnerability in the specified Firefox versions.
Mitigation Recommendations
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 to these versions or later to remediate the issue. No additional mitigation steps are indicated by the vendor advisories.
CVE-2026-12299: Vulnerability in Mozilla Firefox
Description
JIT miscompilation in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37.
CVSS v3.1
Score 5.4medium
Affected software
pkg:github/mozilla/firefox-esrRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-12299 is a vulnerability in Mozilla Firefox caused by JIT miscompilation within the DOM: Core & HTML component. This bug was resolved in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37. The Mozilla advisories classify the impact as high and include references to the bug report (Bug 2043139). The vulnerability is part of a broader set of security fixes released simultaneously, addressing multiple high-impact issues. No known exploits in the wild have been reported. The vendor advisories confirm that the vulnerability is fixed in the specified versions.
Potential Impact
The vulnerability involves just-in-time (JIT) miscompilation in the DOM, which can lead to incorrect code execution within the browser environment. This can undermine browser security and potentially allow attackers to execute unintended code paths. The impact is rated high by Mozilla. There are no reports of active exploitation in the wild. The fix eliminates the vulnerability in the specified Firefox versions.
Mitigation Recommendations
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 to these versions or later to remediate the issue. No additional mitigation steps are indicated by the vendor advisories.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-06-15T15:08:10.195Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-57/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-58/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-59/","vendor":"Mozilla"}]
Threat ID: 6a314c7e0b89be6888b4cc77
Added to database: 6/16/2026, 1:15:42 PM
Last enriched: 6/16/2026, 1:46:29 PM
Last updated: 6/17/2026, 4:59:33 AM
Views: 8
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