Vulnerability · Published May 27, 2025 · Assigned by mozilla
CVE-2025-5269Memory safety bug fixed in Firefox ESR 128.11 and Thunderbird 128.11
High 8.1
In plain English
A high-severity out-of-bounds write 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 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.5%top 58.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Memory safety bug present in Firefox ESR 128.10, and Thunderbird 128.10. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox ESR 128.11 and Thunderbird 128.11.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | firefox | 128.11.0-1.el10_0 | ALSA-2025:8341 |
| AlmaLinux:8 | firefox | 128.11.0-1.el8_10.alma.1 | ALSA-2025:8308 |
| AlmaLinux:9 | firefox | 128.11.0-1.el9_6.alma.1 | ALSA-2025:8293 |
| AlmaLinux:9 | firefox-x11 | 128.11.0-1.el9_6.alma.1 | ALSA-2025:8293 |
| AlmaLinux:10 | thunderbird | 128.11.0-1.el10_0.alma.1 | ALSA-2025:8608 |
| AlmaLinux:8 | thunderbird | 128.11.0-1.el8_10.alma.1 | ALSA-2025:8756 |
| AlmaLinux:9 | thunderbird | 128.11.0-1.el9_6.alma.1 | ALSA-2025:8607 |
| Debian:12 | firefox-esr | 128.11.0esr-1~deb12u1 | DSA-5926-1 |
| Debian:12 | firefox-esr | 128.11.0esr-1~deb12u1 | DEBIAN-CVE-2025-5269 |
| Debian:13 | firefox-esr | 128.11.0esr-1 | DEBIAN-CVE-2025-5269 |
| Debian:14 | firefox-esr | 128.11.0esr-1 | DEBIAN-CVE-2025-5269 |
| Debian:12 | thunderbird | 1:128.11.0esr-1~deb12u1 | DSA-5932-1 |
| Debian:12 | thunderbird | 1:128.11.0esr-1~deb12u1 | DEBIAN-CVE-2025-5269 |
| Debian:13 | thunderbird | 1:128.11.0esr-1 | DEBIAN-CVE-2025-5269 |
| Debian:14 | thunderbird | 1:128.11.0esr-1 | DEBIAN-CVE-2025-5269 |
| Rocky Linux:10 | firefox | 0:128.11.0-1.el10_0 | RLSA-2025:8341 |
| Rocky Linux:8 | firefox | 0:128.11.0-1.el8_10 | RLSA-2025:8308 |
| Rocky Linux:9 | firefox | 0:128.11.0-1.el9_6 | RLSA-2025:8293 |
| Rocky Linux:10 | thunderbird | 0:128.11.0-1.el10_0 | RLSA-2025:8608 |
| Rocky Linux:8 | thunderbird | 0:128.11.0-1.el8_10 | RLSA-2025:8756 |
| Rocky Linux:9 | thunderbird | 0:128.11.0-1.el9_6 | RLSA-2025:8607 |
| Ubuntu:22.04:LTS | thunderbird | 1:128.12.0+build1-0ubuntu0.22.04.1 | USN-7663-1 |
| Ubuntu:22.04:LTS | thunderbird | 1:128.12.0+build1-0ubuntu0.22.04.1 | UBUNTU-CVE-2025-5269 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | see references |
| Mozilla | Thunderbird | see references |
Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- Memory safety bug fixed in Firefox ESR 128.11 and Thunderbird 128.11
- https://www.mozilla.org/security/advisories/mfsa2025-44/
- https://www.mozilla.org/security/advisories/mfsa2025-46/
- https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00043.html