Microsoft Windows Rich Text Edit Control: Remote code execution via heap overflow

Summary

A heap-based buffer overflow in the Windows Rich Text Edit Control allows an unauthorized attacker to execute code over a network. The CVSS vector requires user interaction, so an attacker most likely needs a user to open a crafted document or visit a malicious page. Successful exploitation would give 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 incl. Server Core (10.0.14393.0 to before 10.0.14393.9688)
• Windows Server 2019 incl. 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)

Fixed in

• Fixed builds as listed by the CNA record: see affected builds above (fix at the listed build or later).
• KB article numbers: Unknown.
• Unverified: the fixed build for Windows Server 2025 and Windows 11 24H2 differs between sources; check MSRC.

Workaround

Unknown.

Exploitation

• Microsoft's CVSS temporal metrics: Exploit Code Maturity Unproven, Remediation Level Official fix.
• No known exploitation found in the sources checked (CISA SSVC: exploitation none).
• No public proof of concept found in the sources checked.
• The CVE was published on 10 Nov 2026, so the data is very recent.

Our recommendation

• Apply the Microsoft security update for all affected Windows clients and servers as a priority.
• Check whether older builds such as 1607 and 1809 still receive security updates and whether they are in use.
• Prioritise systems where users open documents from external senders or browse the web.
• Review the MSRC advisory for KB numbers, exact fixed builds and any additional guidance.
• Monitor for exploitation news and re-check the NVD and CISA KEV status.

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: CVE-2026-96081 msrc.microsoft.com
• CVE Record CVE-2026-96081 www.cve.org
• Strix: CVE-2026-96081 www.strix.ai
• CISA KEV alert, October 2026 www.cisa.gov

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, 05:05.