CVE-2026-92018: Vulnerability in Mozilla Firefox
Sandbox escape in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 140.16.
AI Analysis
Technical Summary
CVE-2026-92018 is a sandbox escape vulnerability affecting the DOM: Core & HTML component in Mozilla Firefox. This vulnerability was addressed and fixed in Firefox 156 and the corresponding ESR versions 115.41, 140.16, and 153.3. The sandbox escape could allow an attacker to bypass browser security boundaries. The fix is part of a broader set of security updates released by Mozilla on September 15, 2026, which addressed multiple high-impact vulnerabilities.
Potential Impact
The vulnerability allows an attacker to escape the sandbox environment in Firefox, potentially leading to privilege escalation or unauthorized access beyond the browser's restricted execution environment. This can undermine the security model of the browser and expose the system to further compromise. Mozilla rates the impact as high. There are no reports of active exploitation in the wild.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 156 and Firefox ESR versions 115.41, 140.16, and 153.3. Users and administrators should update to these versions or later to mitigate the risk. No additional mitigation actions are required beyond applying the official patches.
CVE-2026-92018: Vulnerability in Mozilla Firefox
Description
Sandbox escape in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 140.16.
Affected software
Mozilla
Firefox
Mozilla
Thunderbird
pkg:github/mozilla/firefox-esrRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-92018 is a sandbox escape vulnerability affecting the DOM: Core & HTML component in Mozilla Firefox. This vulnerability was addressed and fixed in Firefox 156 and the corresponding ESR versions 115.41, 140.16, and 153.3. The sandbox escape could allow an attacker to bypass browser security boundaries. The fix is part of a broader set of security updates released by Mozilla on September 15, 2026, which addressed multiple high-impact vulnerabilities.
Potential Impact
The vulnerability allows an attacker to escape the sandbox environment in Firefox, potentially leading to privilege escalation or unauthorized access beyond the browser's restricted execution environment. This can undermine the security model of the browser and expose the system to further compromise. Mozilla rates the impact as high. There are no reports of active exploitation in the wild.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 156 and Firefox ESR versions 115.41, 140.16, and 153.3. Users and administrators should update to these versions or later to mitigate the risk. No additional mitigation actions are required beyond applying the official patches.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-09-15T12:33:37.558Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-90/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-91/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-92/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-93/","vendor":"Mozilla"}]
Threat ID: 6aa93e6055bf5e2cf5d30fdc
Added to database: 09/15/2026, 12:47:28 UTC
Last enriched: 09/15/2026, 13:32:37 UTC
Last updated: 09/16/2026, 03:18:32 UTC
Views: 5
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.