CVE-2026-56451 Auth bypass in Opcenter X
Unauthenticated attackers can forge JWTs to bypass authentication and impersonate any user, including administrators, in Siemens Opcenter X.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-56451?
CVE-2026-56451 is a critical authentication bypass vulnerability in Siemens Opcenter X, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability has been identified in Opcenter X (All versions < V2604). Affected applications do not properly validate the algorithm specified in the JSON Web Token (JWT) header. This could allow an unauthenticated remote attacker to forge arbitrary JWT, bypass authentication mechanisms and impersonate any user including administrative accounts, potentially gaining full unauthorized access to the application.
Weakness: CWE-347
Which versions are affected by CVE-2026-56451?
How do I fix CVE-2026-56451?
No fix has been published for CVE-2026-56451 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-2026-56451 being exploited?
There is no known exploitation of CVE-2026-56451 in the wild and no public exploit code.
Sources
Also known as GHSA-j4h7-9cc4-7f3r.