Windows Print Spooler: Heap buffer overflow enables local privilege escalation

Summary

A heap-based buffer overflow in the Windows Print Spooler Components allows an attacker with a valid low-privilege account to elevate privileges on the local system. The attack requires local access and has high complexity. Successful exploitation would give the attacker high confidentiality, integrity and availability impact on the affected system.

Affected

• Windows 10 Version 1607 (10.0.14393.0 to before 10.0.14393.9688)
• Windows 10 Version 1809 (10.0.17763.0 to before 10.0.17763.9487)
• Windows 10 Version 21H2 (10.0.19044.0 to before 10.0.19044.7846)
• Windows 10 Version 22H2 (10.0.19045.0 to before 10.0.19045.7846)
• Windows 11 Version 23H2 (10.0.22631.0 to before 10.0.22631.7711)
• Windows 11 Version 24H2 (10.0.26100.0 to before 10.0.26100.9974)
• Windows 11 Version 25H2 (10.0.26200.0 to before 10.0.26200.9974)
• Windows 11 Version 26H1 (10.0.28000.0 to before 10.0.28000.3501)
• Windows 11 Version 26H2 (10.0.26300.0 to before 10.0.26300.9974)
• Windows Server 2016, including Server Core (10.0.14393.0 to before 10.0.14393.9688)
• Windows Server 2019, including Server Core (10.0.17763.0 to before 10.0.17763.9487)
• Windows Server 2022 (10.0.20348.0 to before 10.0.20348.5870)
• Windows Server 2025: Unknown in the official record

Fixed in

• Fixed in the November 2026 Windows updates, per the CVE record. Build numbers are listed in the affected section above.
• Windows Server 2025: Unknown. A third-party source names build 10.0.26100.33822, which is not verified by Microsoft.
• Check the MSRC update guide for the KB number for each build.

Workaround

• Unknown. No Microsoft-documented workaround was found.
• As a general measure, disable the Print Spooler service on systems that do not need printing and restrict local logon rights.

Exploitation

• Known exploitation in the wild: No evidence found.
• CISA KEV: No listing found at the time of writing.
• Public proof of concept: None found for this CVE.
• CISA SSVC assessment: Exploitation none, not automatable, total technical impact.

Our recommendation

• Install the November 2026 Windows security updates on all affected systems, prioritising servers and domain controllers.
• If printing is not required on a system, disable the Print Spooler service.
• Restrict local logon rights and review accounts with local access.
• Check the MSRC advisory and CISA KEV for updates on this CVE.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• Microsoft Security Update Guide (MSRC) msrc.microsoft.com
• CVE.org record (Microsoft CNA) www.cve.org
• Strix (third-party aggregator) www.strix.ai

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 11 Nov 2026, 09:26.