CVE-2025-8027
firefox: thunderbird: JavaScript engine only wrote partial return value to stack
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · July 23, 2025
Updated · June 30, 2026
Description
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue: On 64-bit platforms, IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack. Baseline-JIT, however, reads the entire 64 bits.
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 · 7.5CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE-457 · Use of Uninitialized Variable