CVE-2026-9308

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.

Score

CVSS 3.1 5.4 Medium

Status

Analyzed - security@mozilla.org

Published

2026-06-01

Last modified

2026-06-01

Weaknesses

CWE-79

Affected products

• Firefox (Mozilla)
• Firefox For Ios (Mozilla)

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2039422
• https://www.mozilla.org/security/advisories/mfsa2026-53/