CVE-2026-53900

MEDIUM 4.3CVE-2026-53900 · Published 16/06/2026 · updated 26/10/2026

In short

CVE-2026-53900 is a MEDIUM (CVSS 4.3) vulnerability affecting firefox mobile (mozilla).
Chance of exploitation in the next 30 days (EPSS): 0.10%, higher than 0.82% of all vulnerabilities.
Fix: update to 152.0 or later.

Package	Affected versions	Patched versions
firefox mobile mozilla	`< 152.0`	`152.0`

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.

References

bugzilla.mozilla.org/show_bug.cgi · Permissions Required
mozilla.org/security/advisories/mfsa2026-56 · Vendor Advisory

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Package

Affected versions

Patched versions

firefox mobile

mozilla

< 152.0

152.0

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