CVE-2026-90453: Cisa Malcolm

Low severity, CVSS 3.5. EPSS: 0.2% chance of exploitation in the next 30 days.

A file-upload handler redirects the authenticated client's browser to a URL taken directly from that same request's Referer header, without validating it against the application's own origin. This allows an authenticated attacker to craft a request that causes another user's browser to be redirected to an arbitrary external destination after completing an upload.

Affected products

• Cisa Malcolm: before v26.06.0 (fixed in v26.06.0)

Published 2026-09-11. Last modified 2026-10-02.