Vulnerability · Published Jun 16, 2026 · Assigned by mozilla
CVE-2026-12312Memory safety bug fixed in Thunderbird 152
High 7.5
In plain English
A high-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 0.3% (higher than 17% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.3%top 83.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Memory safety bug fixed in Thunderbird 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, 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-2026-12312 |
| Debian:13 | firefox-esr | 140.12.0esr-1~deb13u1 | DEBIAN-CVE-2026-12312 |
| Debian:14 | firefox-esr | 140.12.0esr-1 | DEBIAN-CVE-2026-12312 |
| Debian:12 | thunderbird | 1:140.12.0esr-1~deb12u1 | DEBIAN-CVE-2026-12312 |
| Debian:13 | thunderbird | 1:140.12.0esr-1~deb13u1 | DEBIAN-CVE-2026-12312 |
| Debian:14 | thunderbird | 1:140.12.0esr-1 | DEBIAN-CVE-2026-12312 |
| 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 | mozjs102 | no fix listed | UBUNTU-CVE-2026-12312 |
| Ubuntu:24.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-12312 |
| Ubuntu:24.04:LTS | mozjs115 | no fix listed | UBUNTU-CVE-2026-12312 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2026-12312 |
| Ubuntu:22.04:LTS | mozjs91 | no fix listed | UBUNTU-CVE-2026-12312 |
| Ubuntu:22.04:LTS | thunderbird | no fix listed | UBUNTU-CVE-2026-12312 |
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:N/S:U/C:H/I:N/A:N