CVE-2025-11721 — Improper Restriction of Operations within the Bounds of a Memory Buffer in Mozilla Firefox

CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer8 documents7 sources
Severity
9.8CRITICALNVD
EPSS
0.1%
top 81.01%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Mozilla FirefoxMozilla Thunderbird
Timeline
PublishedOct 14

Description

Memory safety bug present in Firefox 143 and Thunderbird 143. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 144 and Thunderbird 144.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 3.9 | Impact: 5.9

Affected Packages2 packages

▶NVDmozilla/firefox143.0 — 144.0
▶NVDmozilla/thunderbird143.0 — 144.0

🔴Vulnerability Details

3
CVEList
Memory safety bug fixed in Firefox 144 and Thunderbird 144↗2025-10-14
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OSV
CVE-2025-11721: Memory safety bug present in Firefox 143 and Thunderbird 143↗2025-10-14
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GHSA
GHSA-r25g-xjc5-pcrv: Memory safety bug present in Firefox 143 and Thunderbird 143↗2025-10-14
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📋Vendor Advisories

4
Red Hat
thunderbird: firefox: Memory safety bug fixed in Firefox 144 and Thunderbird 144↗2025-10-14
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Debian
CVE-2025-11721: firefox - Memory safety bug present in Firefox 143 and Thunderbird 143. This bug showed ev...↗2025
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Mozilla
Mozilla Foundation Security Advisory 2025-84: CVE-2025-11721↗
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Mozilla
Mozilla Foundation Security Advisory 2025-81: CVE-2025-11721↗
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CVE-2025-11721 — Mozilla Firefox vulnerability | cvebase