Security readout for executives and security teams
Plain-English summary
CVE-2026-25171 is a Windows local privilege escalation flaw in Windows Authentication Methods. An attacker who already has authorized local access could potentially gain higher privileges. This is not described as remote initial access, but it matters because it can turn a foothold on a workstation or server into broader system control.
Executive priority
Patch on normal high-severity Windows timelines, with accelerated handling for critical servers and systems accessible to many users. The business risk is privilege escalation after an attacker or insider already has local access, not unauthenticated remote compromise based on provided evidence.
Technical view
The issue is a use-after-free vulnerability in Windows Authentication Methods, mapped to CWE-416. The CVSS 3.1 score is 7.0 with local attack vector, high complexity, low privileges required, no user interaction, unchanged scope, and high confidentiality, integrity, and availability impact. Microsoft lists official remediation availability.
Likely exposure
Organizations running the listed Windows 10, Windows 11, Windows Server 2012 through 2025, and Server Core variants may be exposed until patched. Exposure is highest where standard users, contractors, or compromised low-privilege accounts can log on locally or execute code on affected systems.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. The CVSS vector indicates exploitation requires local access, low privileges, no user interaction, and high attack complexity. Treat this primarily as a post-compromise privilege escalation risk.
Researcher notes
Evidence is limited to the CVE summary, CVSS vector, affected Microsoft product list, and MSRC advisory reference. No exploit mechanics, indicators, workaround details, or active exploitation claims are present in the provided bundle. Avoid inferring exploitability beyond local authorized privilege escalation.
Mitigation direction
- Apply Microsoft security updates referenced by the MSRC advisory.
- Prioritize domain controllers, jump hosts, servers, and shared workstations.
- Restrict local logon and code execution for low-privilege users.
- Monitor Microsoft guidance for revised affected-version or workaround details.
- Reduce standing local administrator rights across Windows fleets.
Validation and detection
- Inventory Windows builds against the affected product list.
- Confirm relevant Microsoft updates are installed on each affected system.
- Check vulnerability management tools for CVE-2026-25171 detection coverage.
- Review EDR telemetry for suspicious local privilege escalation behavior.
- Verify high-risk servers and Server Core systems are included in patch reporting.
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-416: 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-2026-25171 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
- 7 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/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:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C15.9microsoftVulnerability scoring details
Base CVSS 3.1 score
7HighVector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/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
- Windows Authentication 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.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.