CVE-2026-61921Important
Windows Remote Desktop Client Information Disclosure Vulnerability
Assessment
Out-of-bounds read in Remote Desktop Client allows an unauthorized attacker to disclose information over a network.
- Severity
- Important
- CVSS base score
- 6.5CVSS:3.1/
AV:N/ AC:L/ PR:N/ UI:R/ S:U/ C:H/ I:N/ A:N/ E:U/ RL:O/ RC:C - Impact
- Information Disclosure
- EPSS, next 30 days
- 0.9%Higher than 58.7% of scored CVEs · FIRST model run 26 Sep 2026 · about EPSS
- Exploitability
- Exploitation Less Likely
- Publicly disclosed
- No
- Customer action
- Required: apply the update
- Component
- Remote Desktop Client
- Weakness
- CWE-125: Out-of-bounds Read
- Issued by
- Microsoft
- Published
- 11 Aug 2026 · August 2026
- Last revised
- 11 Aug 2026
Updates that fix it
13 KBs| KB | Type | Restart | Applies to | Other CVEs |
|---|---|---|---|---|
| KB5120228 | Security Hotpatch Update | Required | Windows Server 2025, Windows Server 2025 (Server Core installation) | All CVEs in KB5120228 |
| KB5120229 | Security Hotpatch Update | Required | Windows Server 2022, Windows Server 2022 (Server Core installation) | All CVEs in KB5120229 |
| KB5120233 | Security Update | Required | Windows Server 2025, Windows Server 2025 (Server Core installation) | All CVEs in KB5120233 |
| KB5120238 | Security Update | Required | Windows 10 Version 1809 for 32-bit Systems, Windows 10 Version 1809 for x64-based Systems, Windows Server 2019 and 1 more | All CVEs in KB5120238 |
| KB5120240 | Security Update | Required | Windows 11 Version 23H2 for ARM64-based Systems, Windows 11 Version 23H2 for x64-based Systems | All CVEs in KB5120240 |
| KB5120242 | Security Update | Required | Windows Server 2022, Windows Server 2022 (Server Core installation) | All CVEs in KB5120242 |
| KB5120249 | Security Update | Required | Windows 10 Version 21H2 for 32-bit Systems, Windows 10 Version 21H2 for ARM64-based Systems, Windows 10 Version 21H2 for x64-based Systems and 3 more | All CVEs in KB5120249 |
| KB5120385 | Monthly Rollup | Required | Windows Server 2012 R2, Windows Server 2012 R2 (Server Core installation) | All CVEs in KB5120385 |
| KB5120386 | Monthly Rollup | Required | Windows Server 2012, Windows Server 2012 (Server Core installation) | All CVEs in KB5120386 |
| KB5120418 | Security Update | Required | Windows 10 Version 1607 for 32-bit Systems, Windows 10 Version 1607 for x64-based Systems, Windows Server 2016 and 1 more | All CVEs in KB5120418 |
| KB5120994 | Security Hotpatch Update | Required | Windows 11 Version 24H2 for ARM64-based Systems, Windows 11 Version 24H2 for x64-based Systems, Windows 11 Version 25H2 for ARM64-based Systems and 1 more | All CVEs in KB5120994 |
| KB5121000 | Security Update | Required | Windows 11 Version 26H1 for ARM64-based Systems, Windows 11 version 26H1 for x64-based Systems | All CVEs in KB5121000 |
| KB5121003 | Security Update | Required | Windows 11 Version 24H2 for ARM64-based Systems, Windows 11 Version 24H2 for x64-based Systems, Windows 11 Version 25H2 for ARM64-based Systems and 1 more | All CVEs in KB5121003 |
Affected products
ESU, Windows30 affected products
- Windows 10 Version 1607 for 32-bit Systems
- Windows 10 Version 1607 for x64-based Systems
- Windows 10 Version 1809 for 32-bit Systems
- Windows 10 Version 1809 for x64-based Systems
- Windows 10 Version 21H2 for 32-bit Systems
- Windows 10 Version 21H2 for ARM64-based Systems
- Windows 10 Version 21H2 for x64-based Systems
- Windows 10 Version 22H2 for 32-bit Systems
- Windows 10 Version 22H2 for ARM64-based Systems
- Windows 10 Version 22H2 for x64-based Systems
- Windows 11 Version 23H2 for ARM64-based Systems
- Windows 11 Version 23H2 for x64-based Systems
- Windows 11 Version 24H2 for ARM64-based Systems
- Windows 11 Version 24H2 for x64-based Systems
- Windows 11 Version 25H2 for ARM64-based Systems
- Windows 11 Version 25H2 for x64-based Systems
- Windows 11 Version 26H1 for ARM64-based Systems
- Windows 11 version 26H1 for x64-based Systems
- Windows Server 2012
- Windows Server 2012 (Server Core installation)
- Windows Server 2012 R2
- Windows Server 2012 R2 (Server Core installation)
- Windows Server 2016
- Windows Server 2016 (Server Core installation)
- Windows Server 2019
- Windows Server 2019 (Server Core installation)
- Windows Server 2022
- Windows Server 2022 (Server Core installation)
- Windows Server 2025
- Windows Server 2025 (Server Core installation)