CVE-2025-14333 — Out-of-bounds Write in Mozilla Firefox

CWE-787 — Out-of-bounds WriteCWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer11 documents8 sources
Severity
8.1HIGHNVD
EPSS
0.1%
top 75.16%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Mozilla ThunderbirdMozilla Firefox
Timeline
PublishedDec 9

Description

Memory safety bugs present in Firefox ESR 140.5, Thunderbird ESR 140.5, Firefox 145 and Thunderbird 145. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 146, Firefox ESR 140.6, Thunderbird 146, and Thunderbird 140.6.

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 2.2 | Impact: 5.9

Affected Packages3 packages

▶NVDmozilla/firefox< 140.6.0+1
▶NVDmozilla/thunderbird< 140.6.0+1
▶Debianmozilla/thunderbird< 1:140.6.0esr-1~deb11u1+3

🔴Vulnerability Details

3
OSV
CVE-2025-14333: Memory safety bugs present in Firefox ESR 140↗2025-12-09
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CVEList
Memory safety bugs fixed in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146↗2025-12-09
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GHSA
GHSA-4mm6-6c2q-x3fp: Memory safety bugs present in Firefox ESR 140↗2025-12-09
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📋Vendor Advisories

6
Red Hat
firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146↗2025-12-09
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Debian
CVE-2025-14333: firefox - Memory safety bugs present in Firefox ESR 140.5, Thunderbird ESR 140.5, Firefox ...↗2025
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Mozilla
Mozilla Foundation Security Advisory 2025-96: CVE-2025-14333↗
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Mozilla
Mozilla Foundation Security Advisory 2025-95: CVE-2025-14333↗
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Mozilla
Mozilla Foundation Security Advisory 2025-94: CVE-2025-14333↗
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🕵️Threat Intelligence

1
Wiz
CVE-2025-14333 Impact, Exploitability, and Mitigation Steps | Wiz↗
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CVE-2025-14333 — Out-of-bounds Write in Mozilla Firefox | cvebase