Mozilla Foundation Security Advisory 2026-56
Security Vulnerabilities fixed in Firefox for iOS 152.0
- Announced
- June 16, 2026
- Impact
- high
- Products
- Firefox for iOS
- Fixed in
-
- Firefox for iOS 152
#CVE-2026-53899: Cross-origin cookies could be leaked when opening a PDF link
- Reporter
- Muneaki Nishimura
- Impact
- high
Description
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.
References
#CVE-2026-53900: Cookie injection was possible when opening a PDF link
- Reporter
- Muneaki Nishimura
- Impact
- high
Description
Firefox for iOS preserved cookies set on the initial PDF request across cross-origin HTTP redirects in TemporaryDocument, allowing a malicious site to inject arbitrary cookies into requests to an unrelated target domain.