CVE-2025-6436CWE-119

CVE-2025-6436

High · published June 24, 2025

CVSS v3.1
8.1
EPSS
4%
Percentile
91.0
In the wild
Unconfirmed
What it is

Memory safety bugs present in Firefox 139 and Thunderbird 139. 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 140 and Thunderbird 140.

The record
Technical detail
CVSS v3.1
8.1 · HIGH
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.04256 · 91.0th percentile
Weakness
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer
Published
2025-06-24T17:15Z
Affected products (2)
ProductVersionsFixed in
mozilla/firefox< 140.0140.0
mozilla/thunderbird< 140.0140.0
References (3)
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1941377%2C1960948%2C1966187%2C1966505%2C1970764%2C1942930 · [email protected]https://www.mozilla.org/security/advisories/mfsa2025-51/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2025-54/ · [email protected]
EPSS history
Timeline
  • 24 JUN 12:28Z
    Memory safety bugs fixed in Firefox 140 and Thunderbird 140
    cvelistv5