Security readout for executives and security teams
Plain-English summary
This Siemens industrial software issue can let an unauthenticated remote attacker crash affected systems by triggering a flaw in the User Management Component. The impact described is denial of service, not data theft or code execution. For operational technology environments, availability loss can still create meaningful production or monitoring risk.
Executive priority
Treat as a high-priority availability risk for Siemens-controlled environments, especially where process visibility or user management availability is operationally important. Prioritize inventory, network isolation, and vendor-guided updates.
Technical view
CVE-2025-40796 is a CWE-125 out-of-bounds read in the integrated Siemens UMC component. The CVSS 4.0 vector is network-accessible, low complexity, no privileges, and no user interaction, with high vulnerable-system availability impact. Affected entries include SIMATIC PCS neo V4.1, V5.0, V6.0 before V6.0 SP1 Update 1, and UMC before V2.15.1.3.
Likely exposure
Exposure is likely limited to organizations running Siemens SIMATIC PCS neo or standalone/integrated UMC in reachable industrial networks. Internet exposure is not stated in the sources; validate network reachability rather than assuming it.
Exploitation context
The source bundle says an unauthenticated remote attacker could cause denial of service. CISA KEV status is false, and no cited source in the bundle confirms active exploitation or public exploit availability.
Researcher notes
Evidence supports remote unauthenticated denial of service through an out-of-bounds read in UMC. The bundle does not establish confidentiality impact, integrity impact, active exploitation, or exploit availability. Product-specific fixed paths for all PCS neo branches are not fully described in the provided data.
Mitigation direction
- Inventory SIMATIC PCS neo and UMC versions across OT and engineering networks.
- Update SIMATIC PCS neo V6.0 to V6.0 SP1 Update 1 or later where applicable.
- Update UMC to V2.15.1.3 or later where applicable.
- For V4.1 and V5.0, check Siemens SSA-722410 for product-specific remediation guidance.
- Restrict network access to UMC and PCS neo management services.
Validation and detection
- Confirm whether SIMATIC PCS neo V4.1, V5.0, or V6.0 is deployed.
- Confirm whether UMC versions are earlier than V2.15.1.3.
- Check whether affected services are reachable from untrusted or enterprise networks.
- Review monitoring for unexpected UMC or PCS neo service crashes.
- Map Siemens advisory guidance to each deployed product version.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-125: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2025-40796 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.7 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——siemensCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6siemensVulnerability scoring details
Base CVSS 4.0 score
8.7HighVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://cert-portal.siemens.com/productcert/html/ssa-722410.htmlCVE reference, siemens
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Read
Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.