Vulnerability · Published Jun 16, 2026 · Assigned by mozilla
CVE-2026-12330Incorrect boundary conditions in the Internationalization component
Medium 5.4
In plain English
A medium-severity memory corruption 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 0.2% (higher than 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)5.4Medium
Exploit odds (30 days)0.2%top 94.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Incorrect boundary conditions in the Internationalization component. This vulnerability was fixed in Firefox ESR 140.12, Firefox ESR 115.37, and Thunderbird 140.12.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | firefox | 140.12.0-1.el10_2 | ALSA-2026:27733 |
| AlmaLinux:8 | firefox | 140.12.0-1.el8_10.alma.1 | ALSA-2026:27717 |
| AlmaLinux:9 | firefox | 140.12.0-1.el9_8.alma.1 | ALSA-2026:27734 |
| AlmaLinux:9 | firefox-x11 | 140.12.0-1.el9_8.alma.1 | ALSA-2026:27734 |
| AlmaLinux:10 | thunderbird | 140.12.0-1.el10_2.alma.1 | ALSA-2026:30846 |
| AlmaLinux:8 | thunderbird | 140.12.0-1.el8_10.alma.1 | ALSA-2026:33445 |
| AlmaLinux:9 | thunderbird | 140.12.0-1.el9_8.alma.1 | ALSA-2026:29940 |
| Debian:12 | firefox-esr | 140.12.0esr-1~deb12u1 | DEBIAN-CVE-2026-12330 |
| Debian:13 | firefox-esr | 140.12.0esr-1~deb13u1 | DEBIAN-CVE-2026-12330 |
| Debian:14 | firefox-esr | 140.12.0esr-1 | DEBIAN-CVE-2026-12330 |
| Debian:12 | thunderbird | 1:140.12.0esr-1~deb12u1 | DEBIAN-CVE-2026-12330 |
| Debian:13 | thunderbird | 1:140.12.0esr-1~deb13u1 | DEBIAN-CVE-2026-12330 |
| Debian:14 | thunderbird | 1:140.12.0esr-1 | DEBIAN-CVE-2026-12330 |
| Rocky Linux:10 | firefox | 0:140.12.0-1.el10_2 | RLSA-2026:27733 |
| Rocky Linux:8 | firefox | 0:140.12.0-1.el8_10 | RLSA-2026:27717 |
| Rocky Linux:9 | firefox | 0:140.12.0-1.el9_8 | RLSA-2026:27734 |
| Rocky Linux:10 | thunderbird | 0:140.12.0-1.el10_2 | RLSA-2026:30846 |
| Rocky Linux:8 | thunderbird | 0:140.12.0-1.el8_10 | RLSA-2026:33445 |
| Rocky Linux:9 | thunderbird | 0:140.12.0-1.el9_8 | RLSA-2026:29940 |
| Ubuntu:22.04:LTS | thunderbird | no fix listed | UBUNTU-CVE-2026-12330 |
| Ubuntu:24.04:LTS | thunderbird | no fix listed | UBUNTU-CVE-2026-12330 |
| Ubuntu:25.10 | thunderbird | no fix listed | UBUNTU-CVE-2026-12330 |
| Ubuntu:26.04:LTS | thunderbird | no fix listed | UBUNTU-CVE-2026-12330 |
| Ubuntu:26.10 | thunderbird | no fix listed | UBUNTU-CVE-2026-12330 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | see references |
| Mozilla | Thunderbird | see references |
Weakness: CWE-119 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N