Security readout for executives and security teams
Plain-English summary
Microsoft Entra ID contains an origin-validation flaw that could let an unauthenticated remote attacker gain elevated privileges. Successful exploitation could compromise confidentiality, integrity, and availability across affected security boundaries. The supplied sources do not identify affected versions, tenant configurations, or prerequisites beyond the published CVSS assessment.
Executive priority
Treat this as an immediate identity-security priority because Entra privileges can control access across connected business systems. Assign an owner now, obtain Microsoft’s applicability determination, verify remediation, and review privileged activity. Current evidence supports severe potential impact but does not confirm exploitation or every tenant’s exposure.
Technical view
CVE-2026-42901 is classified as CWE-346, an origin validation error. Its CVSS 3.1 score is 10.0: network-accessible, low complexity, no privileges or user interaction required, with changed scope and high confidentiality, integrity, and availability impacts. Exact vulnerable components and versions are unspecified.
Likely exposure
Organizations using Microsoft Entra ID should treat potential exposure as broad until Microsoft guidance confirms otherwise. The bundle lists Microsoft Entra but provides no affected versions, CPEs, deployment conditions, or configuration-based exclusions, preventing precise exposure determination from these sources alone.
Exploitation context
The supplied bundle does not establish active exploitation, and the CVE is not listed as KEV. The CVSS vector reports network reachability, low attack complexity, no required privileges, and no user interaction. Exploit maturity is recorded as unproven, so practical reliability and prerequisites remain unclear.
Researcher notes
Public details are limited to an origin-validation error and the CVSS assessment. The bundle does not specify the flawed endpoint, trust-boundary logic, affected versions, observable indicators, or remediation mechanics. Defensive investigation should focus on privilege changes and Microsoft-provided indicators without assuming a particular exploitation technique.
Mitigation direction
- Review Microsoft’s CVE advisory for tenant-specific remediation and affected-service details.
- Apply Microsoft-prescribed updates or service-side remediation as soon as confirmed applicable.
- Restrict unnecessary administrative access and review privileged Entra roles pending remediation.
- Escalate to Microsoft support if tenant exposure or remediation status remains unclear.
Validation and detection
- Confirm whether Microsoft identifies your Entra tenant or configuration as affected.
- Verify Microsoft-prescribed remediation is applied or the service reports resolved status.
- Review Entra audit and sign-in logs for unexplained privilege or role changes.
- Investigate unauthorized administrative actions and newly assigned privileged roles.
- Document affected tenants, remediation evidence, and review results.
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-346: 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-2026-42901 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
- 10 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
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
1 official scoreWe 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:C/C:H/I:H/A:H/E:U/RL:O/RC:C3.96microsoftVulnerability scoring details
Base CVSS 3.1 score
10CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
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
- Microsoft Entra ID Elevation of Privilege VulnerabilityCVE reference, microsoft · vendor-advisory, patch
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.
Origin Validation Error
Origin Validation Error represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.