CVE-2026-90453 Open Redirect in Malcolm
An authenticated attacker can redirect other users to arbitrary external sites via a crafted Referer header during file upload in Malcolm.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-90453?
CVE-2026-90453 is a medium-severity vulnerability in CISA Malcolm, published on 11 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-601
Which versions are affected by CVE-2026-90453?
How do I fix CVE-2026-90453?
No fix has been published for CVE-2026-90453 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-90453 being exploited?
There is no known exploitation of CVE-2026-90453 in the wild and no public exploit code.
Sources
Also known as GHSA-q82q-369g-qpv8.