Security readout for executives and security teams
Plain-English summary
This Siemens SIMATIC issue is a stored web-script injection flaw. A highly privileged engineering user could place malicious content in a Technology Object name. When another authorized user opens the Motion Control Diagnostics page, the code runs in that user’s web session. It is serious for OT environments, but it requires prior authenticated project-download rights and user interaction.
Executive priority
Prioritize in OT sites using affected Siemens controllers, especially where multiple engineers access device web pages. Treat as urgent but not internet-wide: exploitation needs high privileges and a second user action.
Technical view
CVE-2026-25787 is CWE-79 in affected Siemens SIMATIC Drive Controller and ET 200SP CPU web interfaces. The Motion Control Diagnostics page does not properly validate or sanitize Technology Object names. CVSS 4.0 is 9.3 critical, with network attack vector, low complexity, high privileges required, and passive user interaction.
Likely exposure
Exposure is likely limited to environments using the listed Siemens SIMATIC controllers where users can download TIA projects and access the web interface. The source bundle lists products but does not provide precise affected firmware versions beyond unclear version entries.
Exploitation context
No active exploitation is stated in the provided sources, and KEV is false. Exploitation requires an authenticated attacker authorized to download a TIA project, plus a benign privileged user opening the affected diagnostics page.
Researcher notes
The key weakness is stored XSS via Technology Object name rendering. The impact is session-scoped execution in the victim’s web interface context. Product/version evidence in the bundle is incomplete, so rely on Siemens advisory details for final scoping.
Mitigation direction
- Review Siemens SSA-688146 for exact affected versions, updates, and workarounds.
- Restrict TIA project download rights to trusted engineering accounts only.
- Limit device web interface access to dedicated OT management networks.
- Review Technology Object names for unexpected script-like content before deployment.
- Apply Siemens-provided updates or mitigations when confirmed applicable.
Validation and detection
- Inventory listed Siemens SIMATIC Drive Controller and ET 200SP CPU models.
- Confirm whether the web interface and Motion Control Diagnostics page are used.
- Identify accounts authorized to download TIA projects into affected devices.
- Review recent TIA project changes involving Technology Object names.
- Check Siemens SSA-688146 for current remediation and version details.
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-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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-2026-25787 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
- Critical
- CVSS
- 9.3 (4.0)
- Known Exploited
- No
- Published
Vector: 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
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:H/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H——siemensCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H2.36siemensVulnerability scoring details
Base CVSS 4.0 score
9.3CriticalVector: 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
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/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-688146.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.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.