CVE-2026-9309

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

Published: Jun 1, 2026Updated: Jul 22, 2026 Sources: CVE List NVDCWE-79

5.4MEDIUM

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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:RUser Interaction

Required

Scope

S:UScope

Unchanged

Impact

C:LConfidentiality

Low

I:LIntegrity

Low

A:NAvailability

None

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Weaknesses

CWE-79

Affected Products

Mozilla

oss-project·USaka mozilla corp.

firefoxOn-premDesktop App

Consumer Software / browser

Firefox for iOS

Consumer Software

Exploitability

Official Patch Available

Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques

Execution

Initial Access

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References

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

bugzilla.mozilla.org

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

mozilla.org

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