CVE-2026-27662

Severity: high (CVSS 7.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-12 · updated 2026-10-26
Weakness: CWE-1188

Description

Affected devices do not properly restrict access to the web browser via the Control Panel when no corresponding security mechanisms are in place. This could allow an unauthenticated attacker to gain unauthorized access to the web browser, potentially enabling the discovery of backdoors, performing unauthorized actions, or exploiting misconfigurations that may lead to further system compromise.

Affected products

Siemens SIMATIC HMI MTP1000 Unified Comfort Panel: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1000 Unified Comfort Panel hygienic: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1000 Unified Comfort Panel hygienic neutral design: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1000, Unified Comfort Panel neutral: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1200 Comfort Pro for stand (expandable, flange at the bottom): before V21 — fixed in V21
Siemens SIMATIC HMI MTP1200 Comfort Pro for support arm (expandable, round tube) and extension unit: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1200 Comfort Pro for support arm (not extendable, flange on top): before V21 — fixed in V21
Siemens SIMATIC HMI MTP1200 Comfort Pro neutral design for stand (expandable, flange at the bottom): before V21 — fixed in V21
Siemens SIMATIC HMI MTP1200 Comfort Pro neutral design for support arm (expandable, round tube) and extensio: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1200 Comfort Pro neutral design for support arm (not extendable, flange on top): before V21 — fixed in V21
Siemens SIMATIC HMI MTP1200 Unified Comfort Panel: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1200 Unified Comfort Panel hygienic: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1200 Unified Comfort Panel hygienic neutral design: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1200 Unified Comfort Panel neutral design: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1500 Comfort Pro for stand (expandable, flange at the bottom): before V21 — fixed in V21
Siemens SIMATIC HMI MTP1500 Comfort Pro for support arm (expandable, round tube) and extension unit: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1500 Comfort Pro for support arm (not extendable, flange on top): before V21 — fixed in V21
Siemens SIMATIC HMI MTP1500 Comfort Pro neutral design for stand (expandable, flange at the bottom): before V21 — fixed in V21
Siemens SIMATIC HMI MTP1500 Comfort Pro neutral design for support arm (expandable, round tube) and extensio: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1500 Comfort Pro neutral design for support arm (not extendable, flange on top): before V21 — fixed in V21
Siemens SIMATIC HMI MTP1500 Unified Comfort Panel: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1500 Unified Comfort Panel hygienic: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1500 Unified Comfort Panel hygienic neutral design: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1500 Unified Comfort Panel neutral design: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1900 Comfort Pro for stand (expandable, flange at the bottom): before V21 — fixed in V21
Siemens SIMATIC HMI MTP1900 Comfort Pro for support arm (expandable, round tube) and extension unit: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1900 Comfort Pro for support arm (not extendable, flange on top): before V21 — fixed in V21
Siemens SIMATIC HMI MTP1900 Comfort Pro neutral design for stand (expandable, flange at the bottom): before V21 — fixed in V21
Siemens SIMATIC HMI MTP1900 Comfort Pro neutral design for support arm (expandable, round tube) and extensio: before V21 — fixed in V21
Siemens SIMATIC HMI MTP1900 Comfort Pro neutral design for support arm (not extendable, flange on top): before V21 — fixed in V21

How to fix

Upgrade to a fixed version: Siemens SIMATIC HMI MTP1000 Unified Comfort Panel V21; Siemens SIMATIC HMI MTP1000 Unified Comfort Panel hygienic V21; Siemens SIMATIC HMI MTP1000 Unified Comfort Panel hygienic neutral design V21; Siemens SIMATIC HMI MTP1000, Unified Comfort Panel neutral V21; Siemens SIMATIC HMI MTP1200 Comfort Pro for stand (expandable, flange at the bottom) V21; Siemens SIMATIC HMI MTP1200 Comfort Pro for support arm (expandable, round tube) and extension unit V21; Siemens SIMATIC HMI MTP1200 Comfort Pro for support arm (not extendable, flange on top) V21; Siemens SIMATIC HMI MTP1200 Comfort Pro neutral design for stand (expandable, flange at the bottom) V21; Siemens SIMATIC HMI MTP1200 Comfort Pro neutral design for support arm (expandable, round tube) and extensio V21; Siemens SIMATIC HMI MTP1200 Comfort Pro neutral design for support arm (not extendable, flange on top) V21; Siemens SIMATIC HMI MTP1200 Unified Comfort Panel V21; Siemens SIMATIC HMI MTP1200 Unified Comfort Panel hygienic V21. Check the vendor advisory for mitigations.

References

https://cert-portal.siemens.com/productcert/html/ssa-387223.html

Get alerted when CVE-2026-27662 or the next vulnerability affects your stack