High Cryptography

CVE-2025-40801 — Improper Certificate Validation in Siemens COMOS V10.6

A vulnerability has been identified in COMOS V10.6 (All versions < V10.6.1), COMOS V10.6 (All versions < V10.6.1), JT Bi-Directional Translator for STEP (All versions), NX V2412 (All versions < V2412.8900 with Cloud Entitlement (bundled as NX X)), NX V2506 (All versions < V2506.6000 with Cloud Entitlement (bundled as NX X)), Simcenter 3D (All versions < V2506.6000 with Cloud Entitlement (bundled as Simcenter X Mechanical)), Simcenter Femap (All versions < V2506.0002 with Cloud Entitlement (bundled as Simcenter X Mechanical)), Simcenter Studio (All versions < V2506.0001), Simcenter System Architect (All versions < V2506.0001), Tecnomatix Plant Simulation (All versions < V2504.0007). The SALT SDK is missing server certificate validation while establishing TLS connections to the authorization server. This could allow an attacker to perform a man-in-the-middle attack.

Published Dec 9, 2025 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: siemens

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.3% (30-day exploitation probability)+3
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.26%

ahead of 17% of scored CVEs · Oct 16, 2026

Affects

Siemens

COMOS V10.6 and 8 more

CVSS base

8.1

High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Siemens COMOS V10.6, Siemens JT Bi-Directional Translator for STEP, Siemens NX V2412…).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (cryptography), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Siemens	COMOS V10.6	< V10.6.1	Vulnerable	CVE Program (cve.org) e CISA ADP
Siemens	JT Bi-Directional Translator for STEP	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Siemens	NX V2412	< V2412.8900	Vulnerable	CVE Program (cve.org) e CISA ADP
Siemens	NX V2506	< V2506.6000	Vulnerable	CVE Program (cve.org) e CISA ADP
Siemens	Simcenter 3d	< V2506.6000	Vulnerable	CVE Program (cve.org) e CISA ADP
Siemens	Simcenter Femap	< V2506.0002	Vulnerable	CVE Program (cve.org) e CISA ADP
Siemens	Simcenter Studio	< V2506.0001	Vulnerable	CVE Program (cve.org) e CISA ADP
Siemens	Simcenter System Architect	< V2506.0001	Vulnerable	CVE Program (cve.org) e CISA ADP
Siemens	Tecnomatix Plant Simulation	< V2504.0007	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

High

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.2	CVSS 4.0	Critical	—	—	productcert@siemens.com via NIST National Vulnerability Database
9.2	CVSS 4.0	Critical	—	—	siemens via CVE Program (cve.org) e CISA ADP
8.1	CVSS 3.1	High	2.2	5.9	productcert@siemens.com via NIST National Vulnerability Database
8.1	CVSS 3.1	High	—	—	siemens via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: productcert@siemens.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-295 · Improper Certificate Validation

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 16, 2026 · 4 reading(s) · max 0.26%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Check TLS negotiations and unexpected certificates in the component’s traffic.

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · siemens/comos v10.6, siemens/jt bi-directional translator for step, siemens/nx v2412, siemens/nx v2506, siemens/simcente
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 8.1
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Deferred
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
2025
CVE published
Dec 9, 2025 · siemens

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

2 on the record

cert-portal.siemens.com/productcert/html/ssa-212953.html
NIST National Vulnerability Database
cert-portal.siemens.com/productcert/html/ssa-710408.html
NIST National Vulnerability Database

Elsewhere on this site

Siemens
every CVE for this vendor

Cryptography
same class

CWE-295
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-59086 Stack-based Buffer Overflow in Siemens Simcenter Femap Aug 11, 2026
High CVE-2026-59701 Out-of-bounds Read in Siemens Simcenter Femap Aug 11, 2026
High CVE-2026-59700 Out-of-bounds Read in Siemens Simcenter Femap Aug 11, 2026
Medium CVE-2025-40945 Untrusted Search Path in Siemens COMOS V10.4.5 Jul 14, 2026
High CVE-2025-12659 Heap-based buffer overflow in Siemens Simcenter Femap May 12, 2026
Low CVE-2025-40745 A vulnerability has been identified in Siemens Software Center (All versions < V3.5.8.2),... Apr 14, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2025-40801 is "Improper Certificate Validation in Siemens COMOS V10.6", rated High. It affects COMOS V10.6 (Siemens); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.1 describes technical severity. EPSS 0.26% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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