CVE-2026-4699

Incorrect boundary conditions in the Layout: Text and Fonts component

CVSS 7.5 HIGHEPSS 0.5%CWE-754

Vexday Risk Score

21Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 7.5EPSS 0.5%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

24 Mar 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

Mozilla · Firefox Mozilla · Thunderbird

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References

https://bugzilla.mozilla.org/show_bug.cgi?id=2021863 https://www.mozilla.org/security/advisories/mfsa2026-20/https://www.mozilla.org/security/advisories/mfsa2026-21/https://www.mozilla.org/security/advisories/mfsa2026-22/https://www.mozilla.org/security/advisories/mfsa2026-23/https://www.mozilla.org/security/advisories/mfsa2026-24/