Improper access control in Firefox for Android and Mozilla Firefox - CVE-2026-8971
Published: May 19, 2026
Vulnerability identifier: #VU131861
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-2026-8971
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 Networking: JAR component when handling cross-origin content. A remote attacker can trigger the flaw to bypass the same-origin policy.
Affected software
Firefox for Android
Mozilla Firefox
Mozilla Thunderbird
Mozilla Firefox
Mozilla Thunderbird
How to mitigate CVE-2026-8971
Install security update from vendor's website.
Firefox for Android - update to 151.0
Mozilla Firefox - update to 151.0
Mozilla Thunderbird - update to 151.0
Mozilla Firefox - update to 151.0
Mozilla Thunderbird - update to 151.0