CVE-2025-1020
firefox: thunderbird: Memory safety bugs fixed in Firefox 135 and Thunderbird 135
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · February 4, 2025
Updated · May 21, 2026
Description
A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue: 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.
Statement
Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 8.8CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')