CVE-2026-9309
MediumCVSS 5.4Exploitation Probability (EPSS)
Low risk5th percentile - higher than 5% of all known CVEs
Summary
Firefox for iOS Reader View did not properly escape HTML tags in JSON-LD metadata, allowing a malicious page to inject markup that changed Reader View behavior and leaked sensitive URL parameters, potentially leading to arbitrary JavaScript execution in an internal origin. Fixed in version 151.2.
Risk Assessment
The risk includes arbitrary JavaScript execution in an internal browser context, which could lead to data theft or further attacks.
Recommendation
Update Firefox for iOS to version 151.2 or later.
Other vulnerabilities in Firefox for iOS
See all- CVE-2023-49060Critical
In Firefox for iOS, an attacker could access internal pages or data by exfiltrating a security key from ReaderMode via the referrerpolicy attribute. This affects Firefox for iOS versions prior to 120.
- CVE-2026-14906Medium
A vulnerability in Firefox for iOS allowed malicious page titles to overwrite saved PDF files or bundled content within the application sandbox. This issue was fixed in version 152.4.
- CVE-2026-13356Medium
A malicious webpage could interrupt a pending navigation by enqueuing a synchronous JavaScript dialog, causing the browser UI to display the destination origin in the address bar while continuing to render attacker-controlled content. This vulnerability was fixed in Firefox for iOS 152.3.
- CVE-2026-53900Medium
Firefox for iOS preserved cookies set on the initial PDF request across cross-origin HTTP redirects, allowing a malicious site to inject arbitrary cookies into requests to an unrelated target domain.
- CVE-2026-53899Medium
Firefox for iOS used partial domain matching when attaching cookies to PDF requests, allowing a malicious site on a suffix domain to receive cookies belonging to the target site.
- CVE-2026-9308Medium
Firefox for iOS Reader View replaced page content in its HTML template before replacing other internal placeholders, allowing a malicious page to include a placeholder string later substituted with JSON-LD data, potentially resulting in arbitrary JavaScript execution. Fixed in version 151.2.
- CVE-2026-9078Medium
Firefox for iOS incorrectly displayed specially crafted RTL and IDN domain names in the link preview UI. This could allow an attacker to impersonate trusted origins. The vulnerability was fixed in Firefox for iOS 151.1.
- CVE-2026-8706Medium
Firefox for iOS hosted Reader mode on an unauthenticated local web server, allowing another app on the same device to request arbitrary URLs and receive responses with the signed-in user's cookies. Fixed in Firefox for iOS 151.0.
- CVE-2024-43113Medium
The contextual menu for links could provide an opportunity for cross-site scripting attacks. This vulnerability affects Firefox for iOS < 129.
- CVE-2024-43112Medium
Long pressing on a download link could potentially provide a means for cross-site scripting. This vulnerability affects Firefox for iOS < 129.
Original NVD description (English source)
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.