Improper access control in Mozilla products - CVE-2026-12304
Published: June 16, 2026
Vulnerability identifier: #VU134620
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-12304
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Mozilla
Affected software:
Firefox for Android
Mozilla Firefox
Firefox ESR
Firefox for Android
Mozilla Firefox
Firefox ESR
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass the same-origin policy.
The vulnerability exists due to improper access control in the Networking: Cookies component when handling cookies. A remote attacker can trigger the vulnerable behavior to bypass the same-origin policy.
How to mitigate CVE-2026-12304
Install security update from vendor's website.