CVE-2026-53900

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. This vulnerability was fixed in Firefox for iOS 152.0.

CVSS Vector

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2043204
• https://www.mozilla.org/security/advisories/mfsa2026-56/