CVE-2026-9309

MEDIUM

Arbitrary JavaScript execution in internal pages via Reader View JSON-LD injection

Title source: cna

Description

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.

References (2)

Core 2

Core References

https://bugzilla.mozilla.org/show_bug.cgi?id=2036573

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