Improper access control in Mozilla products - CVE-2026-74956
Published: August 18, 2026
Vulnerability identifier: #VU144082
CSH Severity: Medium
CVSS v4: 5.1 [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]
CVE-ID: CVE-2026-74956
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass the same-origin policy.
The vulnerability exists due to improper access control in the DOM: Service Workers component when handling crafted web content. A remote attacker can cause the victim to visit a specially crafted website to bypass the same-origin policy.
User interaction is required to visit a crafted website or URL.
Affected software
Firefox for Android
Mozilla Firefox
Firefox ESR
Mozilla Firefox
Firefox ESR
How to mitigate CVE-2026-74956
Install security update from vendor's website.
Firefox for Android - update to 154.0
Mozilla Firefox - update to 154.0
Firefox ESR - update to 153.1.0
Mozilla Firefox - update to 154.0
Firefox ESR - update to 153.1.0