CVE-2026-16351: Vulnerability in Mozilla Firefox
Sandbox escape due to use-after-free in the DOM: Navigation component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13.
AI Analysis
Technical Summary
CVE-2026-16351 is a use-after-free vulnerability in the DOM: Navigation component of Mozilla Firefox that enables sandbox escape. This vulnerability was addressed and fixed in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13. The Mozilla advisories indicate the impact is high and that the issue was reported by Yaqoub Aldurayhim. The advisories also mention that no attacks in the wild are currently known, but exploit code is publicly available. The fix is part of a broader set of memory safety improvements released in these Firefox versions.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to escape the browser sandbox, potentially leading to arbitrary code execution outside the browser's restricted environment. This elevates the risk of system compromise if exploited. However, there are no confirmed reports of active exploitation in the wild at this time.
Mitigation Recommendations
A fix is available and has been incorporated in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13. Users and administrators should update affected Firefox installations to these versions or later to mitigate this vulnerability. No additional mitigation steps are indicated by the vendor advisories.
CVE-2026-16351: Vulnerability in Mozilla Firefox
Description
Sandbox escape due to use-after-free in the DOM: Navigation component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13.
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-16351 is a use-after-free vulnerability in the DOM: Navigation component of Mozilla Firefox that enables sandbox escape. This vulnerability was addressed and fixed in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13. The Mozilla advisories indicate the impact is high and that the issue was reported by Yaqoub Aldurayhim. The advisories also mention that no attacks in the wild are currently known, but exploit code is publicly available. The fix is part of a broader set of memory safety improvements released in these Firefox versions.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to escape the browser sandbox, potentially leading to arbitrary code execution outside the browser's restricted environment. This elevates the risk of system compromise if exploited. However, there are no confirmed reports of active exploitation in the wild at this time.
Mitigation Recommendations
A fix is available and has been incorporated in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13. Users and administrators should update affected Firefox installations to these versions or later to mitigate this vulnerability. No additional mitigation steps are indicated by the vendor advisories.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-07-20T21:55:50.743Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-68/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-69/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-70/","vendor":"Mozilla"}]
Threat ID: 6a5f6cb92a4a8d598926240e
Added to database: 07/21/2026, 12:57:29 UTC
Last enriched: 07/21/2026, 13:44:05 UTC
Last updated: 07/21/2026, 21:18:23 UTC
Views: 4
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.