CVE-2026-27662 Missing authorization in SIMATIC HMI MTP1000 Unified Comfort Panel
Unauthenticated attackers can access the web browser on Siemens HMI panels, potentially discovering backdoors or exploiting misconfigurations for further compromise.
- 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-2026-27662?
CVE-2026-27662 is a high-severity missing authorization vulnerability in Siemens SIMATIC HMI MTP1000 Unified Comfort Panel, published on 12 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Affected devices do not properly restrict access to the web browser via the Control Panel when no corresponding security mechanisms are in place. This could allow an unauthenticated attacker to gain unauthorized access to the web browser, potentially enabling the discovery of backdoors, performing unauthorized actions, or exploiting misconfigurations that may lead to further system compromise.
Weakness: CWE-1188
Which versions are affected by CVE-2026-27662?
How do I fix CVE-2026-27662?
No fix has been published for CVE-2026-27662 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-27662 being exploited?
There is no known exploitation of CVE-2026-27662 in the wild and no public exploit code.
Sources
Also known as GHSA-fg9h-cf2h-vjrx.