CVE-2026-9308: Vulnerability in Mozilla Firefox for iOS
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.
AI Analysis
Technical Summary
Firefox for iOS Reader View had a vulnerability due to replacing page content in its HTML template before substituting internal placeholders. This sequence allowed a malicious page to include a placeholder string that, when replaced with JSON-LD data, could lead to arbitrary JavaScript execution. The vulnerability was addressed and fixed in Firefox for iOS 151.2 as per Mozilla's security advisory MFSA2026-53.
Potential Impact
The vulnerability allows arbitrary JavaScript execution within Firefox for iOS Reader View, which could be exploited by a malicious page. This could lead to unauthorized script execution, potentially compromising user data or browser behavior. The vendor rates the impact as high.
Mitigation Recommendations
An official fix is available in Firefox for iOS version 151.2. Users and administrators should update to this version or later to remediate the vulnerability. No additional mitigation steps are required beyond applying the official update.
CVE-2026-9308: Vulnerability in Mozilla Firefox for iOS
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.
CVSS v3.1
Score 5.4medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Firefox for iOS Reader View had a vulnerability due to replacing page content in its HTML template before substituting internal placeholders. This sequence allowed a malicious page to include a placeholder string that, when replaced with JSON-LD data, could lead to arbitrary JavaScript execution. The vulnerability was addressed and fixed in Firefox for iOS 151.2 as per Mozilla's security advisory MFSA2026-53.
Potential Impact
The vulnerability allows arbitrary JavaScript execution within Firefox for iOS Reader View, which could be exploited by a malicious page. This could lead to unauthorized script execution, potentially compromising user data or browser behavior. The vendor rates the impact as high.
Mitigation Recommendations
An official fix is available in Firefox for iOS version 151.2. Users and administrators should update to this version or later to remediate the vulnerability. No additional mitigation steps are required beyond applying the official update.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-05-22T18:16:25.742Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-53/","vendor":"Mozilla"}]
Threat ID: 6a1d832ee29bf47b50f6aa3e
Added to database: 6/1/2026, 1:03:42 PM
Last enriched: 6/1/2026, 1:33:41 PM
Last updated: 6/2/2026, 7:07:33 AM
Views: 8
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