Firefox iOS Reader View XSS via JSONLD (fixed in v151.2)
CVE-2026-9309 Published on June 1, 2026

Arbitrary JavaScript execution in internal pages via Reader View JSON-LD injection
Firefox for iOS Reader View did not properly escape HTML tags in JSON-LD metadata. A malicious page could inject markup that changed Reader View behavior and leaked sensitive URL parameters. These parameters could then be used to access internal pages, potentially resulting in arbitrary JavaScript execution in an internal origin. This vulnerability was fixed in Firefox for iOS 151.2.

NVD


Products Associated with CVE-2026-9309

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Mozilla Firefox
 

Affected Versions

Mozilla Firefox for iOS: