Microsoft Streaming Service Proxy Elevation of Privilege Vulnerability

cisa required action Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

1. 2023-09-12 0-day patched (Project Zero)
2. 2023-09-12 Added to CISA KEV
3. 2023-09-12 Published
4. 2023-10-03 CISA patch deadline
5. 2025-02-04 CISA SSVC: exploitation active

Added

3 y ago (2023-09-12)

Patch by

2023-10-03 (3 y ago)

Ransomware

Not known

Required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Vendor, product

Microsoft, Streaming Service Proxy

CISA name

Microsoft Streaming Service Proxy Privilege Escalation Vulnerability

Detected in real attacks while still unknown to the vendor and the public, per Google Project Zero's 0day In-the-Wild tracker.

Patched

2023-09-12

Details

project zero root cause analysis

Exploitation

Active, exploited in the wild

Automatable

no

Technical impact

total

Assessed

21 mo ago (2025-02-04)

27.91% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-08).

• Microsoft Windows 10 Version 1809
• Microsoft Windows Server 2019
• Microsoft Windows Server 2019 (Server Core installation)
• Microsoft Windows Server 2022
• Microsoft Windows 11 version 21H2
• Microsoft Windows 10 Version 21H2
• Microsoft Windows 11 version 22H2
• Microsoft Windows 10 Version 22H2

Weakness

• CWE-416 Use After Free

• msrc.microsoft.com /update-guide/vulnerability/CVE-2023-36802

  vendor-advisory, patch

• cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-36802

  government-resource, us-government-resource

• CVE List CVE-2023-36802
• NVD CVE-2023-36802

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.