UBUNTU-CVE-2026-116773

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Source
https://ubuntu.com/security/CVE-2026-116773
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116773.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-116773
Upstream
Published
2026-10-27T21:18:00Z
Modified
2026-10-28T20:17:46Z
Severity
  • 4.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. Prior to 0.65.0, the client Session::process_packet path in russh/src/client/encrypted.rs accepts repeated packets encoded with russh's private msg::EXT_INFO = 7 before authentication, while the standards-compliant EXT_INFO message number 82 does not reach the affected handler. The handle_ext_info function appends every parsed extension name to received_extensions without clearing, deduplicating, or bounding the vector. A malicious SSH server that deliberately sends private message number 7 can therefore retain an unbounded number of attacker-controlled extension names for the session lifetime, causing progressive client memory exhaustion. This issue is fixed in version 0.65.0.

References

Affected packages

Ubuntu:26.10 / rust-russh

Package

Name
rust-russh
Purl
pkg:deb/ubuntu/rust-russh?arch=source&distro=stonking

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.57.1-2

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "librust-russh-dev",
            "binary_version":  "0.57.1-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-116773.json"