Code Injection in Firefox for iOS - CVE-2026-9308
Published: June 1, 2026
Vulnerability identifier: #VU133136
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-9308
CWE-ID: CWE-94
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Mozilla
Affected software:
Firefox for iOS
Firefox for iOS
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary JavaScript.
The vulnerability exists due to improper neutralization of special elements in Reader View HTML template processing when rendering a malicious page in Reader View. A remote attacker can include a crafted placeholder string in page content to execute arbitrary JavaScript.
How to mitigate CVE-2026-9308
Install security update from vendor's website.