CVE-2025-1020

EUVD-2025-1975
Memory safety bugs present in Firefox 134 and Thunderbird 134. 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 135 and Thunderbird 135.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
9.8 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Affected Products (NVD)
VendorProductVersion
mozillafirefox
𝑥
< 135.0
mozillathunderbird
131.0 ≤
𝑥
< 135.0
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
firefox
sid
149.0.2-1
fixed
Common Weakness Enumeration
References
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1939063%2C1942169
https://www.mozilla.org/security/advisories/mfsa2025-07/
https://www.mozilla.org/security/advisories/mfsa2025-11/