CVE Intelligence
High Memory corruption

CVE-2025-40797 — A vulnerability has been identified in SIMATIC PCS neo V4.1 (All versions), SIMATIC PCS neo V5.0 ...

A vulnerability has been identified in SIMATIC PCS neo V4.1 (All versions), SIMATIC PCS neo V5.0 (All versions), SIMATIC PCS neo V6.0 (All versions < V6.0 SP1 Update 1), User Management Component (UMC) (All versions < V2.15.1.3). Affected products contain a out-of-bounds read vulnerability in the integrated UMC component. This could allow an unauthenticated remote attacker to cause a denial of service condition.

Published Sep 9, 2025 · Updated Oct 18, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: siemens

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 0.5% (30-day exploitation probability)+6
  • 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
0.52%
ahead of 43% of scored CVEs · Oct 18, 2026
Affects
Siemens
Simatic Pcs Neo and 5 more
CVSS base
7.5
High · 3 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
No
can an attacker script the kill-chain steps
Technical impact
Partial
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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Siemens Simatic Pcs Neo, Siemens SIMATIC PCS neo V4.1, Siemens SIMATIC PCS neo V5.0…).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Siemens Simatic Pcs Neo version 4.1version 5.0 Vulnerable NIST National Vulnerability Database
Siemens SIMATIC PCS neo V4.1 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Siemens SIMATIC PCS neo V5.0 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Siemens SIMATIC PCS neo V6.0 < V6.0 SP1 Update 1 Vulnerable CVE Program (cve.org) e CISA ADP
Siemens User Management Component < 2.15.1.3 Vulnerable NIST National Vulnerability Database
Siemens User Management Component (UMC) < V2.15.1.3 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
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Every base score collected

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

ScoreVersionSeverityExpl.ImpactScored by
8.7 CVSS 4.0 High — — productcert@siemens.com via NIST National Vulnerability Database
8.7 CVSS 4.0 High — — siemens via CVE Program (cve.org) e CISA ADP
7.5 CVSS 3.1 High 3.9 3.6 productcert@siemens.com via NIST National Vulnerability Database
7.5 CVSS 3.1 High — — GitHub, Inc. via GitHub Security Advisories
7.5 CVSS 3.1 High — — siemens via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (score shown at the top: productcert@siemens.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-125 · Out-of-bounds Read

Other CVEs with this weakness →

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).
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · siemens/simatic pcs neo v4.1, siemens/simatic pcs neo v5.0, siemens/simatic pcs neo v6.0, siemens/user management compon
    Oct 18, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 18, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 18, 2026
  • Affected products added · siemens/simatic pcs neo, siemens/user management component
    Oct 18, 2026 · NIST National Vulnerability Database
  • CVSS changed · 7.5
    Oct 18, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 18, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 18, 2026 · Alertas do Telegram
  • 2025
  • CVE published
    Sep 9, 2025 · siemens

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 18, 2026 – Oct 18, 2026
  • 1× Official description updated · Oct 18, 2026 – Oct 18, 2026

References

3 on the record

Elsewhere on this site

Siemens
every CVE for this vendor
Memory corruption
same class
CWE-125
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-25656 Uncontrolled Search Path Element in Siemens Sinec Nms Feb 10, 2026
  • CVE-2025-40798 A vulnerability has been identified in SIMATIC PCS neo V4.1 (All versions), SIMATIC PCS neo V5.0 ... Sep 9, 2025
  • CVE-2025-40795 A vulnerability has been identified in SIMATIC PCS neo V4.1 (All versions), SIMATIC PCS neo V5.0 ... Sep 9, 2025
  • CVE-2025-40796 A vulnerability has been identified in SIMATIC PCS neo V4.1 (All versions), SIMATIC PCS neo V5.0 ... Sep 9, 2025
  • CVE-2024-54678 Deserialization of Untrusted Data in Siemens SIMATIC PCS neo V4.1 Aug 12, 2025
  • CVE-2025-30033 Uncontrolled Search Path Element in Siemens Automation License Manager V6.0 Aug 12, 2025

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-2025-40797 is "A vulnerability has been identified in SIMATIC PCS neo V4.1 (All versions), SIMATIC PCS neo V5.0 ...", rated High. It affects Simatic Pcs Neo (Siemens); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.5 describes technical severity. EPSS 0.52% 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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