SIMATIC Drive Controller CPU 1504D TF: Improper Neutralization of Input During Web Page Generation
CVE-2026-25786 is a critical-severity improper neutralization of input during web page generation vulnerability in SIMATIC Drive Controller CPU 1504D TF from Siemens, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. The record lists version V3.1.6 as the first without the flaw, so updating SIMATIC Drive Controller CPU 1504D TF to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.37% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update SIMATIC Drive Controller CPU 1504D TF to V3.1.6 or a later version.
- Update SIMATIC Drive Controller CPU 1507D TF to V3.1.6 or a later version.
- Update SIMATIC ET 200SP CPU 1510SP F-1 PN to V2.9.9 or V4.1.6, whichever matches your release line, or a later version.
Affected products and versions
Version data comes from the organisation that assigned the CVE; 35 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (siemens.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.3 | Critical | CNA (siemens.com) |
| CVSS 3.1 | 9.1 | Critical | CNA (siemens.com) |
Official description
Affected devices do not properly validate and sanitize PLC/station name rendered on the "communication" parameters page of the web interface. This could allow an authenticated attacker who is authorized to download a TIA project into the product, to inject malicious scripts into the page. If a benign user with appropriate rights accesses the "communication" parameters page, the malicious code would be executed in the scope of their web session.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Input During Web Page Generation
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
How developers prevent this class of flaw
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
- Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Improper Neutralization of Input During Web Page Generation vulnerabilities (CWE-79)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in SIMATIC Drive Controller CPU 1504D TF
- 9.6 Critical severity
- 9.6 Critical severity
- 9.6 Critical severity
- 7.1 High severity
- 9.1 Critical severity
- 9.6 Critical severity
Recent Improper Neutralization of Input During Web Page Generation vulnerabilities
- 8.7 High severity
- 8.8 High severity
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- 7.3 High severity
- 8.1 High severity
- 7.2 High severity
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