NTLM hash disclosure via attacker-controlled path
Published Jan 13, 2026 · Updated Jan 13, 2026
External path control in Windows NTLM allows remote attackers to disclose an NTLM hash through a crafted network-delivered file. Microsoft identifies CWE-73 but has not disclosed the accepted filename or path form, the affected NTLM code locus, or the operation that initiates authentication. Exploitation requires user interaction with the crafted file or path; success exposes credential material without reported data alteration or service interruption.
Summary
What happened
External path control in Windows NTLM allows remote attackers to disclose an NTLM hash through a crafted network-delivered file. Microsoft identifies CWE-73 but has not disclosed the accepted filename or path form, the affected NTLM code locus, or the operation that initiates authentication. Exploitation requires user interaction with the crafted file or path; success exposes credential material without reported data alteration or service interruption.
The record
- CVE
- CVE-2026-20925
- Published
- Jan 13, 2026
- Updated
- Jan 13, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-73, T1187
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 13, 2026CVE publishedPublication date reported by the CVE source.
- Jan 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.17763.0 <10.0.17763.8276
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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