CVE-2026-63357: Siemens SIMATIC S7 PLC web server cross-site scripting

CVE-2026-63357 · Severity: medium · CVSS 6.1 · Published 2026-10-13

Siemens SIMATIC S7 programmable logic controllers (PLCs) that manage industrial automation and manufacturing processes contain a vulnerability in their web-based diagnostics interface. An attacker can trick an authorized user into importing a malicious file, which causes malicious JavaScript to execute in the user's browser and perform industrial control operations through the PLC's web server. This could lead to unauthorized changes to PLC configurations or operations.

Technologies: Siemens SIMATIC Drive Controller CPU 1504D TF, Siemens SIMATIC Drive Controller CPU 1507D TF, Siemens SIMATIC ET 200SP CPU 1510SP F-1 PN, Siemens SIMATIC ET 200SP CPU 1510SP-1 PN, Siemens SIMATIC ET 200SP CPU 1512SP F-1 PN, Siemens SIMATIC ET 200SP CPU 1512SP-1 PN, Siemens SIMATIC ET 200SP CPU 1514SP F-2 PN, Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC, Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC2, Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC3 V4. Vendors: Siemens.

Quick answers

Is CVE-2026-63357 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-63357 being exploited in the wild.
How severe is CVE-2026-63357?
Medium severity, with a CVSS score of 6.1, published 13 October 2026.
Which products and versions are affected?
Siemens SIMATIC Drive Controller CPU 1504D TF all versions; Siemens SIMATIC Drive Controller CPU 1507D TF all versions; Siemens SIMATIC ET 200SP CPU 1510SP F-1 PN all versions; Siemens SIMATIC ET 200SP CPU 1510SP-1 PN all versions; and 7 more.
Is there a fix for CVE-2026-63357?
No fixed version is recorded yet. Restrict access to the web-based diagnostics interface to trusted networks and limit user permissions for file import functionality to only those who require it. Avoid importing calculated signal files from untrusted sources. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-63357 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-63357?
Check whether you run Siemens SIMATIC Drive Controller CPU 1504D TF, Siemens SIMATIC Drive Controller CPU 1507D TF, Siemens SIMATIC ET 200SP CPU 1510SP F-1 PN or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Restrict access to the web-based diagnostics interface to trusted networks and limit user permissions for file import functionality to only those who require it. Avoid importing calculated signal files from untrusted sources.

Technical details

The vulnerability is a cross-site scripting (XSS) flaw in the calculated signal file import functionality of the SIMATIC S7-1500 web server. The web interface fails to sanitize calculated signal data before rendering it on the Trace page, allowing attackers to inject malicious JavaScript. Exploitation requires social engineering an authorized user with "Read diagnostics" privileges to import a specially crafted file, after which the injected script executes in the user's browser session with the user's authorization level.

Affected products

  • Siemens SIMATIC Drive Controller CPU 1504D TF all versions
  • Siemens SIMATIC Drive Controller CPU 1507D TF all versions
  • Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC2 all versions
  • Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC3 V4 all versions
  • Siemens SIMATIC ET 200SP Open Controller CPU 1515SP PC all versions
  • Siemens SIMATIC ET 200SP CPU 1510SP F-1 PN all versions
  • Siemens SIMATIC ET 200SP CPU 1510SP-1 PN all versions
  • Siemens SIMATIC ET 200SP CPU 1512SP F-1 PN all versions
  • Siemens SIMATIC ET 200SP CPU 1512SP-1 PN all versions
  • Siemens SIMATIC ET 200SP CPU 1514SP F-2 PN all versions
  • Siemens SIMATIC S7-1500 CPU all versions

Timeline

  • 2026-10-13: disclosed

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.