CVE-2026-9309

5.4 mediumEPSS 0.2%

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.

Severity

CVSS 3.1

5.4 medium

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

EPSS: 0.2% chance of exploitation in the next 30 days; higher than 4% of CVEs (scores of 2026-10-31)
CWE: CWE-79
Published: 2026-06-01
Modified: 2026-07-22
Record from: the NVD, synced 2026-10-19

Affected

mozilla:firefox

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2036573
https://www.mozilla.org/security/advisories/mfsa2026-53/

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