CVE-2026-9308: Mozilla Firefox

Medium severity, CVSS 5.4. EPSS: 0.3% chance of exploitation in the next 30 days.

Firefox for iOS Reader View replaced page content in its HTML template before replacing other internal placeholders. A malicious page could include a placeholder string that was later substituted with JSON-LD data, potentially resulting in arbitrary JavaScript execution. This vulnerability was fixed in Firefox for iOS 151.2.

Affected products

• Mozilla Firefox: before 151.2 (fixed in 151.2)

Published 2026-06-01. Last modified 2026-07-22.