CVE-2026-25786

Critical

Published: 12 May 2026

Published

12 May 2026

Modified

12 May 2026

KEV Added

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Patch

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CVSS Score v4 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Score 0.0037 28.9th percentile

Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-25786 is a critical-severity Cross-site Scripting (CWE-79) vulnerability in Siemens (inferred from references). Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 28.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-29426

Vulnerability details

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.

CWE(s): CWE-79

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

Why these techniques?

Stored XSS (CWE-79) in the authenticated web interface of a device allows script injection via project upload and execution in other users' sessions, directly enabling exploitation of a public-facing application.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0