CVE-2026-63356 Cross-site scripting in SIMATIC Drive Controller CPU 1504D TF
An attacker can execute arbitrary JavaScript in a user's browser by tricking them into importing a malicious CSV trace file into Siemens SIMATIC devices.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-63356?
CVE-2026-63356 is a medium-severity cross-site scripting vulnerability in Siemens SIMATIC Drive Controller CPU 1504D TF, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Affected devices do not properly sanitize calculated signal names contained in imported CSV trace files before including them in error messages on the Trace page. This could allow an attacker to social engineer an authorized user who holds the function right “Read diagnostics” into importing a specially crafted trace file. Attacker-controlled JavaScript could be executed in the user’s browser session when the resulting error message is displayed.
Weakness: CWE-79
Which versions are affected by CVE-2026-63356?
How do I fix CVE-2026-63356?
No fix has been published for CVE-2026-63356 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-63356 being exploited?
There is no known exploitation of CVE-2026-63356 in the wild and no public exploit code.
Sources
Also known as GHSA-739x-j4vq-qrx3.