CVE-2026-4699

CWE-754CWE-787 — Out-of-bounds Write14 documents9 sources
Severity
7.5HIGH
EPSS
0.0%
top 93.66%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
3
Mozilla FirefoxMozilla Firefox ESRMozilla Thunderbird
Timeline
PublishedMar 24

Description

Incorrect boundary conditions in the Layout: Text and Fonts component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitability: 3.9 | Impact: 3.6

Affected Packages6 packages

▶CVEListV5mozilla/firefoxunspecified — 149
▶NVDmozilla/firefox128.0 — 140.9.0+2
▶CVEListV5mozilla/firefox_esrunspecified — 115.34+1
▶Debianfirefox-esr< 140.9.0esr-1~deb11u1+3
▶CVEListV5mozilla/thunderbirdunspecified — 149+1

🔴Vulnerability Details

3
CVEList
Incorrect boundary conditions in the Layout: Text and Fonts component↗2026-03-24
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GHSA
GHSA-2qjw-h8g8-r86f: Incorrect boundary conditions in the Layout: Text and Fonts component↗2026-03-24
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OSV
CVE-2026-4699: Incorrect boundary conditions in the Layout: Text and Fonts component↗2026-03-24
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📋Vendor Advisories

7
Red Hat
firefox: thunderbird: Incorrect boundary conditions in the Layout: Text and Fonts component↗2026-03-24
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Debian
CVE-2026-4699: firefox - Incorrect boundary conditions in the Layout: Text and Fonts component. This vuln...↗2026
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Mozilla
Mozilla Foundation Security Advisory 2026-20: CVE-2026-4699↗
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Mozilla
Mozilla Foundation Security Advisory 2026-22: CVE-2026-4699↗
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Mozilla
Mozilla Foundation Security Advisory 2026-24: CVE-2026-4699↗
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🕵️Threat Intelligence

1
Wiz
CVE-2026-4699 Impact, Exploitability, and Mitigation Steps | Wiz↗
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💬Community

1
Bugzilla
CVE-2026-4699 firefox: thunderbird: Incorrect boundary conditions in the Layout: Text and Fonts component↗2026-03-24
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