CVE-2026-90452 Improper certificate validation in Malcolm
Attackers can bypass certificate validation to impersonate the identity provider and issue forged authentication tokens in Malcolm deployments.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-90452?
CVE-2026-90452 is a medium-severity vulnerability in CISA Malcolm, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Requests from the reverse proxy to the identity-provider service for token discovery, introspection, and credential exchange do not verify the identity provider's server certificate. An attacker positioned on the network path between the proxy and the identity provider could impersonate the identity provider and issue forged authentication tokens accepted by the deployment.
Weakness: CWE-295
Which versions are affected by CVE-2026-90452?
How do I fix CVE-2026-90452?
No fix has been published for CVE-2026-90452 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-90452 being exploited?
There is no known exploitation of CVE-2026-90452 in the wild and no public exploit code.
Sources
Also known as GHSA-vfcm-4hjc-64rr.