CVE-2025-29828: Windows Schannel Remote Code Execution Vulnerability

Overview

Severity

High (CVSS 8.1)

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Category

Remote Code Execution

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2025-Jun

Released

2025-06-10

EPSS Score

0.89% (percentile: 75.5%)

Description

Missing release of memory after effective lifetime in Windows Cryptographic Services allows an unauthorized attacker to execute code over a network.

FAQ

According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? Successful exploitation of this vulnerability requires an attacker to send a large number of messages. How could an attacker exploit the vulnerability? An attacker can exploit this vulnerability by sending malicious fragmented ClientHello messages to a target server that accepts Transport Layer Security (TLS) connections.

Affected Products (11)

Windows

• Windows Server 2022
• Windows Server 2022 (Server Core installation)
• Windows Server 2025 (Server Core installation)
• Windows 11 Version 23H2 for ARM64-based Systems
• Windows 11 Version 23H2 for x64-based Systems
• Windows Server 2022, 23H2 Edition (Server Core installation)
• Windows 11 Version 24H2 for ARM64-based Systems
• Windows 11 Version 24H2 for x64-based Systems
• Windows Server 2025

ESU

• Windows 11 Version 22H2 for ARM64-based Systems
• Windows 11 Version 22H2 for x64-based Systems

Security Updates (6)

• 5060526
• 5060525
• 5060999
• 5060842
• 5060841
• 5060118

Acknowledgments

Anonymous

Revision History

• 2025-06-10: Information published.