Security readout for executives and security teams
Plain-English summary
Mendix Runtime applications may be put at risk because access-rule documentation did not clearly explain special behavior for the System.User entity. Developers could unintentionally allow broad access to user data or privilege-related functions. The risk is serious, but exposure depends on how each Mendix application was configured.
Executive priority
Treat this as urgent configuration risk, not just a software version issue. Assign application owners to review Mendix authorization immediately, especially for customer-facing or workforce identity-related apps. No confirmed active exploitation is cited in the provided sources.
Technical view
CVE-2026-7891 affects Mendix Runtime, described as all versions. It is classified as CWE-277 with CVSS 3.1 score 9.1. The issue is a documentation gap around System.User access rules that can lead to overly permissive application-level authorization, causing confidentiality and integrity impact.
Likely exposure
Organizations running Mendix applications are potentially exposed if their apps define permissive access rules for System.User. Internet-facing apps and apps containing sensitive user profiles, account data, or administrative workflows should be prioritized. The exact exposure is application-specific and cannot be determined from version alone.
Exploitation context
The CVSS vector indicates remote, low-complexity, unauthenticated exploitation without user interaction. However, the provided sources do not state active exploitation, and CISA KEV is false. Practical exploitability depends on whether a deployed Mendix app contains the risky access-rule configuration.
Researcher notes
This appears configuration-dependent and rooted in documentation clarity around System.User behavior. The CVE says all Mendix Runtime versions are affected, but real impact requires checking each app’s access rules. The provided bundle does not include detailed patch information.
Mitigation direction
- Review Siemens SSA-814963 and DIVD Mendix guidance for current remediation direction.
- Audit all Mendix apps for access rules involving System.User.
- Restrict System.User access to least privilege for each application role.
- Prioritize internet-facing apps and apps containing sensitive user data.
- If vendor guidance changes, follow Siemens and DIVD instructions promptly.
Validation and detection
- Inventory deployed Mendix Runtime applications and owners.
- Identify domain access rules referencing System.User.
- Verify non-admin users cannot read sensitive user attributes.
- Verify non-admin users cannot change privilege-related user data.
- Review logs for unusual user-data access or privilege changes.
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-277: 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 lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-7891 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
- 9.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A: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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N3.95.2siemensCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N——siemensVulnerability scoring details
Base CVSS 4.0 score
9.1CriticalVector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
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://csirt.divd.nl/DIVD-2026-00006/CVE reference, siemens · vendor-advisory
- https://www.divd.nl/mendix.htmlCVE reference, siemens · mitigation
- https://cert-portal.siemens.com/productcert/html/ssa-814963.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.
Insecure Inherited Permissions
Insecure Inherited Permissions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.