CVE-2026-90447 Authentication Bypass by Spoofing in Malcolm
An authenticated attacker can spoof a request header to bypass role-based authorization and access elevated privileges in Malcolm.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-90447?
CVE-2026-90447 is a high-severity authentication bypass vulnerability in CISA Malcolm, published on 11 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A routing rule selects between two different authentication mechanisms for the same downstream service based on the value of a client-supplied request header, rather than on any property the client cannot control. An authenticated user in possession of a shared service credential can set this header to route around the primary role-based authorization check and reach the alternate path's fixed, elevated role instead. This allows a low-privileged authenticated attacker who knows the shared credential to perform actions reserved for a higher-privileged role.
Weakness: CWE-290
Which versions are affected by CVE-2026-90447?
How do I fix CVE-2026-90447?
No fix has been published for CVE-2026-90447 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-90447 being exploited?
There is no known exploitation of CVE-2026-90447 in the wild and no public exploit code.
Sources
Also known as GHSA-rh2r-7hqc-wgwc.