CVE-2026-9308

🔶 medium

Summary

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.

CVSS Score

5.4

Medium

EPSS Score

0.0

Exploit Probability

Published Date

2026-06-01

First Seen: 2026-06-02

📊 Relative Risk Intelligence

This CVE is Lower Risk - more severe than 22.9% of all 325,576 vulnerabilities in our database.

#251,158

Below average severity

Severity Percentile

🎯 CISA SSVC Assessment Updated: Jun 1, 2026

🔍 Exploitation Status

None

No known exploits

⚙️ Automatable

Requires human interaction

💥 Technical Impact

Partial

Limited system impact

🏆 Discovered By

Muneaki Nishimura

SSVC data provided by CISA

Last Modified 2026-06-03

Source NVD 🔗

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

CWE IDs (Weakness Types)

CWE-79

📦 Affected Products 1

Vendor	Product	Status	Affected Versions
mozilla	firefox	Affected	< 151.2

🔗 References 2

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

Permissions Required

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

Vendor Advisory

🔗 Related CVEs 6

CVE ID	Severity	CVSS	EPSS	Summary	Published
CVE-2026-10701	⚠️ high	7.5	0.0	Incorrect boundary conditions in the Graphics: Text component. This vulnerability was fixed in Firefox 151.0.3.	2026-06-02
CVE-2026-10702	🔶 medium	4.3	0.0	JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 151.0.3.	2026-06-02
CVE-2026-9309	🔶 medium	5.4	0.0	Firefox for iOS Reader View did not properly escape HTML tags in JSON-LD metadata. A malicious page could inject markup ...	2026-06-01
CVE-2026-9078	🔶 medium	5.4	0.0	Firefox for iOS displayed specially crafted right-to-left (RTL) and internationalized domain names (IDNs) incorrectly in...	2026-05-25
CVE-2026-8945	⚠️ high	7.5	0.1	Sandbox escape in Firefox and Firefox Focus for Android. This vulnerability was fixed in Firefox 151.	2026-05-19
CVE-2026-8946	⚠️ high	7.5	0.1	Incorrect boundary conditions in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 151, Fir...	2026-05-19

These CVEs affect the same products