CVE-2025-4091Improper Restriction of Operations within the Bounds of a Memory Buffer in Mozilla Firefox

Severity
8.1HIGHNVD
EPSS
0.4%
top 36.97%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedApr 29
Latest updateJul 22

Description

Memory safety bugs present in Firefox 137, Thunderbird 137, Firefox ESR 128.9, and Thunderbird 128.9. 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 138, Firefox ESR 128.10, Thunderbird 138, and Thunderbird 128.10.

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< 128.10+1
NVDmozilla/thunderbird< 128.10.0+1
Debianmozilla/thunderbird< 1:128.10.1esr-1~deb11u1+3

🔴Vulnerability Details

3
OSV
CVE-2025-4091: Memory safety bugs present in Firefox 137, Thunderbird 137, Firefox ESR 1282025-04-29
CVEList
Memory safety bugs fixed in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.102025-04-29
GHSA
GHSA-jgr2-rf9j-5fh3: Memory safety bugs present in Firefox 137, Thunderbird 137, Firefox ESR 1282025-04-29

📋Vendor Advisories

7
Ubuntu
Thunderbird vulnerabilities2025-07-22
Red Hat
firefox: thunderbird: Memory safety bugs fixed in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.102025-04-29
Debian
CVE-2025-4091: firefox - Memory safety bugs present in Firefox 137, Thunderbird 137, Firefox ESR 128.9, a...2025
Mozilla
Mozilla Foundation Security Advisory 2025-31: CVE-2025-4091
Mozilla
Mozilla Foundation Security Advisory 2025-32: CVE-2025-4091
CVE-2025-4091 — Mozilla Firefox vulnerability | cvebase