Vulnerability · Published Jun 16, 2026 · Assigned by mozilla
CVE-2026-12318Incorrect boundary conditions in the Libraries component in NSS
High 7.3
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 18% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.3High
Exploit odds (30 days)0.3%top 81.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Incorrect boundary conditions in the Libraries component in NSS. This vulnerability was fixed in Firefox 152 and Thunderbird 152.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | nss | 2:3.87.1-1+deb12u3 | DEBIAN-CVE-2026-12318 |
| Debian:13 | nss | 2:3.110-1+deb13u3 | DEBIAN-CVE-2026-12318 |
| Debian:14 | nss | 2:3.124-1 | DEBIAN-CVE-2026-12318 |
| Ubuntu:22.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-12318 |
| Ubuntu:24.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-12318 |
| Ubuntu:24.04:LTS | mozjs115 | no fix listed | UBUNTU-CVE-2026-12318 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2026-12318 |
| Ubuntu:22.04:LTS | mozjs91 | no fix listed | UBUNTU-CVE-2026-12318 |
| Ubuntu:22.04:LTS | nss | 2:3.98-0ubuntu0.22.04.4 | USN-8481-1 |
| Ubuntu:22.04:LTS | nss | 2:3.98-0ubuntu0.22.04.4 | UBUNTU-CVE-2026-12318 |
| Ubuntu:24.04:LTS | nss | 2:3.98-1ubuntu0.2 | USN-8481-1 |
| Ubuntu:24.04:LTS | nss | 2:3.98-1ubuntu0.2 | UBUNTU-CVE-2026-12318 |
| Ubuntu:25.10 | nss | 2:3.114-1ubuntu0.2 | USN-8481-1 |
| Ubuntu:25.10 | nss | 2:3.114-1ubuntu0.2 | UBUNTU-CVE-2026-12318 |
| Ubuntu:26.04:LTS | nss | 2:3.120-1ubuntu2.1 | UBUNTU-CVE-2026-12318 |
| Ubuntu:26.04:LTS | nss | 2:3.120-1ubuntu2.1 | USN-8481-1 |
| Ubuntu:22.04:LTS | thunderbird | no fix listed | UBUNTU-CVE-2026-12318 |
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:L/I:L/A:L