CVE-2026-4699: Vulnerability in Mozilla Firefox
Incorrect boundary conditions in the Layout: Text and Fonts component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
AI Analysis
Technical Summary
CVE-2026-4699 involves incorrect boundary conditions in the Layout: Text and Fonts component of Mozilla Firefox, leading to potential memory safety issues. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, and Firefox ESR 140.9. The CVSS 3.1 score is 7.5 (high), with attack vector network, low attack complexity, no privileges required, no user interaction, and impacts availability only. The vendor advisory confirms the fix and lists this vulnerability among multiple high-impact memory safety bugs resolved in these versions.
Potential Impact
The vulnerability impacts availability by potentially causing denial-of-service conditions (application crashes) in affected Firefox versions prior to 149 and ESR versions prior to 115.34 and 140.9. There is no direct impact on confidentiality or integrity according to the CVSS vector. Exploitation could disrupt user browsing but does not lead to code execution or data compromise based on current information.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 149, Firefox ESR 115.34, and Firefox ESR 140.9. Users and administrators should update to these versions or later to remediate the issue. No additional mitigation actions are required beyond applying these updates.
CVE-2026-4699: Vulnerability in Mozilla Firefox
Description
Incorrect boundary conditions in the Layout: Text and Fonts component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
CVSS v3.1
Score 7.5high
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-4699 involves incorrect boundary conditions in the Layout: Text and Fonts component of Mozilla Firefox, leading to potential memory safety issues. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, and Firefox ESR 140.9. The CVSS 3.1 score is 7.5 (high), with attack vector network, low attack complexity, no privileges required, no user interaction, and impacts availability only. The vendor advisory confirms the fix and lists this vulnerability among multiple high-impact memory safety bugs resolved in these versions.
Potential Impact
The vulnerability impacts availability by potentially causing denial-of-service conditions (application crashes) in affected Firefox versions prior to 149 and ESR versions prior to 115.34 and 140.9. There is no direct impact on confidentiality or integrity according to the CVSS vector. Exploitation could disrupt user browsing but does not lead to code execution or data compromise based on current information.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 149, Firefox ESR 115.34, and Firefox ESR 140.9. Users and administrators should update to these versions or later to remediate the issue. No additional mitigation actions are required beyond applying these updates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-03-23T23:22:01.062Z
- Cvss Version
- null
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-20/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-21/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-22/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-23/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-24/","vendor":"Mozilla"}]
Threat ID: 69c28784f4197a8e3b3205bd
Added to database: 03/24/2026, 12:45:56 UTC
Last enriched: 07/15/2026, 09:28:42 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 145
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