Vulnerability · Published Jul 22, 2025 · Assigned by mozilla
CVE-2025-8027JavaScript engine only wrote partial return value to stack
Medium 6.5
In plain English
A medium-severity security flaw in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
On 64-bit platforms IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack. Baseline-JIT, however, read the entire 64 bits. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | firefox | 128.13.0-1.el10_0 | ALSA-2025:11797 |
| AlmaLinux:8 | firefox | 128.13.0-1.el8_10.alma.1 | ALSA-2025:11747 |
| AlmaLinux:9 | firefox | 128.13.0-1.el9_6.alma.1 | ALSA-2025:11748 |
| AlmaLinux:9 | firefox-x11 | 128.13.0-1.el9_6.alma.1 | ALSA-2025:11748 |
| AlmaLinux:10 | thunderbird | 128.13.0-3.el10_0.alma.1 | ALSA-2025:12188 |
| AlmaLinux:8 | thunderbird | 128.13.0-3.el8_10.alma.1 | ALSA-2025:13676 |
| AlmaLinux:9 | thunderbird | 128.13.0-3.el9_6.alma.1 | ALSA-2025:12187 |
| Debian:12 | firefox-esr | 128.13.0esr-1~deb12u1 | DEBIAN-CVE-2025-8027 |
| Debian:12 | firefox-esr | 128.13.0esr-1~deb12u1 | DSA-5964-1 |
| Debian:13 | firefox-esr | 128.13.0esr-1 | DEBIAN-CVE-2025-8027 |
| Debian:14 | firefox-esr | 128.13.0esr-1 | DEBIAN-CVE-2025-8027 |
| Debian:12 | thunderbird | 1:128.13.0esr-1~deb12u1 | DSA-5966-1 |
| Debian:12 | thunderbird | 1:128.13.0esr-1~deb12u1 | DEBIAN-CVE-2025-8027 |
| Debian:13 | thunderbird | 1:128.13.0esr-1 | DEBIAN-CVE-2025-8027 |
| Debian:14 | thunderbird | 1:128.13.0esr-1 | DEBIAN-CVE-2025-8027 |
| Rocky Linux:10 | firefox | 0:128.13.0-1.el10_0 | RLSA-2025:11797 |
| Rocky Linux:8 | firefox | 0:128.13.0-1.el8_10 | RLSA-2025:11747 |
| Rocky Linux:9 | firefox | 0:128.13.0-1.el9_6 | RLSA-2025:11748 |
| Rocky Linux:10 | thunderbird | 0:128.13.0-3.el10_0 | RLSA-2025:12188 |
| Rocky Linux:8 | thunderbird | 0:128.13.0-3.el8_10 | RLSA-2025:13676 |
| Rocky Linux:9 | thunderbird | 0:128.13.0-3.el9_6 | RLSA-2025:12187 |
| Ubuntu:22.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2025-8027 |
| Ubuntu:24.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2025-8027 |
| Ubuntu:24.04:LTS | mozjs115 | no fix listed | UBUNTU-CVE-2025-8027 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2025-8027 |
| Ubuntu:22.04:LTS | mozjs91 | no fix listed | UBUNTU-CVE-2025-8027 |
| Ubuntu:22.04:LTS | thunderbird | 1:140.7.1+build1-0ubuntu0.22.04.1 | UBUNTU-CVE-2025-8027 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | see references |
| Mozilla | Thunderbird | see references |
Weakness: CWE-457 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1968423
- https://www.mozilla.org/security/advisories/mfsa2025-56/
- https://www.mozilla.org/security/advisories/mfsa2025-57/
- https://www.mozilla.org/security/advisories/mfsa2025-58/
- https://www.mozilla.org/security/advisories/mfsa2025-59/
- https://www.mozilla.org/security/advisories/mfsa2025-61/
- https://www.mozilla.org/security/advisories/mfsa2025-62/
- https://www.mozilla.org/security/advisories/mfsa2025-63/
- https://lists.debian.org/debian-lts-announce/2025/07/msg00016.html