Local privilege escalation via permissive DKM ACL
Published Jul 14, 2026 · Updated Jul 14, 2026
Access-control weakness in Microsoft AD FS on affected Windows releases allows local authenticated users to elevate privileges. The AD FS DKM container accepts overly permissive ACLs, exposing symmetric key material that protects token-signing private keys. Read access to that material lets attackers decrypt the signing keys and compromise federation trust.
Summary
What happened
Access-control weakness in Microsoft AD FS on affected Windows releases allows local authenticated users to elevate privileges. The AD FS DKM container accepts overly permissive ACLs, exposing symmetric key material that protects token-signing private keys. Read access to that material lets attackers decrypt the signing keys and compromise federation trust.
The record
- CVE
- CVE-2026-56155
- Published
- Jul 14, 2026
- Updated
- Jul 14, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-1220, T1552.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 14, 2026CVE publishedPublication date reported by the CVE source.
- Jul 14, 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 <10.0.17763.9020
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.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities Catalog listingknown exploited catalog
Technologies
Your stack
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Your stack
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