Vulnerability · Published May 19, 2026 · Assigned by mozilla
CVE-2026-8945Sandbox escape in Firefox and Firefox Focus for Android
High 7.5
In plain English
A high-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 31% of all known vulnerabilities).
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.4%top 69.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Sandbox escape in Firefox and Firefox Focus for Android. This vulnerability was fixed in Firefox 151.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-8945 |
| Ubuntu:24.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-8945 |
| Ubuntu:24.04:LTS | mozjs115 | no fix listed | UBUNTU-CVE-2026-8945 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2026-8945 |
| Ubuntu:22.04:LTS | mozjs91 | no fix listed | UBUNTU-CVE-2026-8945 |
| Ubuntu:22.04:LTS | thunderbird | no fix listed | UBUNTU-CVE-2026-8945 |
Affected products (as reported)
Weakness: CWE-693, CWE-653 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2003171
- https://www.mozilla.org/security/advisories/mfsa2026-46/
- https://access.redhat.com/security/cve/CVE-2026-8945 vdb-entry, x_refsource_REDHAT
- RHBZ#2479863 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8945.json x_sadp-csaf-vex