CVE-2026-9308

MEDIUM

Arbitrary JavaScript execution in Reader View due to wrong HTML replacement order

Title source: cna

Description

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.

References (2)

Core 2

Core References

https://bugzilla.mozilla.org/show_bug.cgi?id=2039422

https://www.mozilla.org/security/advisories/mfsa2026-53/

Scores

CVSS v3 5.4

EPSS 0.0016

EPSS Percentile 5.2%

Attack Vector NETWORK

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-79

Status published

Products (2)

mozilla/firefox < 151.2

Mozilla/Firefox for iOS 151.2

Published Jun 01, 2026

Tracked Since Jun 01, 2026