Security readout for executives and security teams
Plain-English summary
A weakness in Windows Hello can let an already-authorized, highly privileged attacker bypass a security control remotely. Successful exploitation could expose or alter sensitive information, but the supplied CVSS assessment indicates no availability impact. The source bundle does not establish exploitation in the wild.
Executive priority
Address through the normal security-update cycle, accelerating systems protecting sensitive data or using Windows Hello broadly. The business risk is unauthorized disclosure or modification after privileged access is obtained. Current evidence does not justify emergency incident status solely from this CVE.
Technical view
CVE-2025-26635 is a Windows Hello weak-authentication issue classified as CWE-1390. It is network-reachable, low complexity, requires high privileges, and needs no user interaction. CVSS 3.1 is 6.5, with high confidentiality and integrity impact but no availability impact.
Likely exposure
Potential exposure includes the listed Windows 10, Windows 11, Windows Server 2019, and Windows Server 2022 editions. Prioritize systems using Windows Hello, but do not infer fixed-build thresholds from the supplied base-version entries. Confirm applicability and update status through Microsoft guidance.
Exploitation context
The bundle marks this CVE as absent from KEV and assigns CVSS exploit maturity E:U, meaning unproven. No supplied source supports active exploitation or public exploit availability. Risk is constrained by the requirement that an attacker already possess high privileges.
Researcher notes
Affected-version data supplies product names and baseline versions but no explicit fixed-build boundaries or KB identifiers. Validation should rely on the current Microsoft advisory. Avoid treating Windows Server exposure or Windows Hello configuration as uniform across deployments. The supplied evidence supports security-feature bypass, not initial access or availability impact.
Mitigation direction
- Review the Microsoft advisory for applicable security updates and installation requirements.
- Deploy applicable Microsoft updates through the organization's tested patch-management process.
- Prioritize exposed or sensitive systems where Windows Hello is enabled.
- Restrict privileged access and investigate unnecessary high-privilege accounts.
Validation and detection
- Inventory systems running the Windows products and editions listed in the source bundle.
- Determine where Windows Hello is enabled and relevant to authentication workflows.
- Compare installed update status with the Microsoft CVE advisory.
- Confirm remediated systems meet Microsoft guidance after patching.
- Monitor privileged authentication activity for unexplained security-control bypass indicators.
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-1390: 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-2025-26635 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
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N/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:H/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C1.25.2microsoftVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N/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 Hello Security Feature Bypass 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.
Weak Authentication
Weak Authentication represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.