CVE-2025-61984: ssh in OpenSSH before 10.1 allows control characters in usernames that originate from certain possibly untrusted sources, potentially leading to code execution when a ProxyCommand is used. The untrusted sources are the command line and %-sequence expansion of a configuration file. (A configuration file that provides a complete literal username is not categorized as an untrusted source.)

Overview

Severity

Low (CVSS 3.6)

CVSS Vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N

Exploit Status

Not Exploited

Patch Tuesday

2025-Oct

Released

2025-10-08

EPSS Score

0.01% (percentile: 1.2%)

FAQ

Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability? One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.

Affected Products (3)

Mariner

• azl3 openssh 9.8p1-4 on Azure Linux 3.0

Open Source Software

• cbl2 openssh 8.9p1-8 on CBL Mariner 2.0
• azl3 openssh 9.8p1-5 on Azure Linux 3.0

Revision History

• 2025-10-08: Information published.