Microsoft Windows: Use-after-free in Windows Audio Service enables privilege escalation
Summary
A use-after-free vulnerability (CWE-416) in the Windows Audio Service allows a local attacker to elevate privileges. An attacker needs a valid low-privilege user session on the affected system, and attack complexity is high. Successful exploitation can lead to full control of the system, so the flaw is typically used after an initial compromise.
Affected
- Windows 11 Version 24H2 (10.0.26100.0 to below 10.0.26100.9711)
- Windows 11 Version 25H2 (10.0.26200.0 to below 10.0.26200.9711)
- Windows 11 Version 26H1 (10.0.28000.0 to below 10.0.28000.3231)
- Windows 11 Version 26H2 (10.0.26300.0 to below 10.0.26300.9711)
- Windows Server 2025 including Server Core (10.0.26100.0 to below 10.0.26100.33650)
Fixed in
- Windows 11 24H2: 10.0.26100.9711
- Windows 11 25H2: 10.0.26200.9711
- Windows 11 26H1: 10.0.28000.3231
- Windows 11 26H2: 10.0.26300.9711
- Windows Server 2025: 10.0.26100.33650 (one source lists this build; verify on the MSRC page)
According to third-party listings, the October 2026 cumulative updates contain the fixes (KB5127648 for 24H2/25H2/26H2, KB5127646 for 26H1, KB5126646 for Server 2025). KB numbers are unconfirmed.
Workaround
Unknown. Microsoft has not published a workaround in the sources reviewed. One unverified third-party source suggests disabling the Windows Audio Service where audio is not needed, which is impractical on most business workstations.
Exploitation
- CISA SSVC: exploitation none, not automatable
- Not listed in the CISA KEV catalogue
- EPSS score 0.0027 (low)
- No public proof of concept found in the searches performed; a targeted search of exploit repositories was not carried out
Our recommendation
- Install the October 2026 cumulative update on all Windows 11 24H2, 25H2, 26H1, 26H2 and Server 2025 systems, prioritising workstations used for external files
- Verify the build number after installation against the MSRC advisory
- Do not defer the update, as Windows 11 24H2 is widely deployed
- Limit local accounts to least privilege and monitor for suspicious processes running under standard users
Information from Microsoft (Patch Tuesday October 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-70118 msrc.microsoft.com
- OpenCVE: CVE-2026-70118 app.opencve.io
- Vulners NVD record: CVE-2026-70118 vulners.com
- Vulners CVE list record: CVE-2026-70118 vulners.com
- Strix: CVE-2026-70118 www.strix.ai
- Vulners MSCVE: MS:CVE-2026-70118 vulners.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 4 Nov 2026, 09:14.
Original description (NVD)
Use after free in Windows Audio Service allows an authorized attacker to elevate privileges locally.
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.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.