Windows Server: Information disclosure in attestation services
Summary
An out-of-bounds read in the Microsoft Azure Attestation service and the Device Health Attestation service allows an unauthenticated attacker to read memory contents over the network. Only confidentiality is affected; integrity and availability are not. The attacker needs network access to the affected service, and the exact trigger is not public.
Affected
- Windows Server 2019 and Windows Server 2019 (Server Core): versions below 10.0.17763.9376
- Windows Server 2022: versions below 10.0.20348.5761
- Windows Server 2025 and Windows Server 2025 (Server Core): versions below 10.0.26100.33650
Fixed in
- Windows Server 2019: build 10.0.17763.9376 (KB5126651)
- Windows Server 2022: build 10.0.20348.5761 or later
- Windows Server 2025: build 10.0.26100.33650 or later
Confirm the fixed builds on the MSRC advisory.
Workaround
Unknown. No official mitigation such as disabling the component is known.
- Install the latest Windows Server security update that contains the fix.
- Monitoring of attestation endpoints for anomalous traffic is a secondary control.
Exploitation
- No evidence of exploitation in the wild found; not listed in CISA KEV.
- CISA SSVC: exploitation none, automatable yes, technical impact partial.
- EPSS below 1% (0.00966). No public proof of concept found.
Our recommendation
- Patch Windows Server 2019, 2022 and 2025 hosts to at least the builds above.
- Check whether the DHA role or the Azure Attestation endpoint is in use, and restrict network access to it if it is not needed.
- Test Exchange hosts before rollout, because of a known Exchange issue in the October 2026 update.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Information disclosure – Microsoft Azure Attestation service and Device Health Attestation Service
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows
- Updates (KB)
- KB5126651, KB5126655, KB5126646
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-69577 msrc.microsoft.com
- NVD record via Vulners vulners.com
- OpenCVE: CVE-2026-69577 app.opencve.io
- VulDB: CVE-2026-69577 vuldb.com
- Strix AI: CVE-2026-69577 www.strix.ai
- Microsoft Message Center MC1506288 mc.merill.net
- Windows Forum: Build 17763.9376 windowsforum.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 2 Nov 2026, 19:32.
Original description (NVD)
Out-of-bounds read in Microsoft Azure Attestation service and Device Health Attestation Service allows an unauthorized attacker to disclose information over a network.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
Affected? We can help.
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