Disclosure summary
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.)
Source-reported weakness categories
CWE-159
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
Microsoft Security Updates (CVRF) · 2025-Oct
Open original source · Updated Oct 07, 2025
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.)
Maximum of vendor-reported product scores; products and fixed builds are associations, not a universal affected-version statement.
Microsoft maximum product score: 3.6
| Vendor | Product / association | Version / bounds |
|---|---|---|
| Microsoft update guide | azl3 openssh 9.8p1-4 on Azure Linux 3.0 | (MSRC status code 3) |
| Microsoft update guide | azl3 openssh 9.8p1-5 on Azure Linux 3.0 | (MSRC status code 3) |
Vendor remediation references
- CBL-Mariner Releases · build 9.8p1-5 · product IDs 19453-17084, 20632-17084
- Vendor guidance · product IDs 19453-17084, 20632-17084
Original records & references
- NIST NVD record
- CVE Program record
- msrc.microsoft.com — Vendor advisory
PUBLISHED 2025-10-07T21:02:05-04:00
MODIFIED 2025-10-07T21:02:05-04:00
INGESTED 2026-10-08T12:45:38-04:00