Eugeny russh up to 0.64.x Agent Server server.rs serve resource consumption

Summaryinfo

A vulnerability was found in Eugeny russh up to 0.64.x and classified as problematic. Impacted is the function russh::keys::agent::server::serve of the file russh/src/keys/agent/server.rs of the component Agent Server. Executing a manipulation can lead to resource consumption. The identification of this vulnerability is CVE-2026-116696. The attack may be launched remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Eugeny russh up to 0.64.x. This vulnerability affects the function russh::keys::agent::server::serve of the file russh/src/keys/agent/server.rs of the component Agent Server. The manipulation with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. CVE summarizes:

russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. Prior to 0.65.0, russh::keys::agent::server::serve in russh/src/keys/agent/server.rs accepts repeated SSH_AGENT_CONSTRAIN_CONFIRM records while adding a key and appends every Constraint::Confirm record to the key's retained constraint vector without a count or memory limit. A process that can connect to the agent socket, including the remote side of a forwarded agent session, can repeatedly add constrained keys and cause renewable memory growth that persists for the process lifetime because keys without a lifetime constraint do not expire. This issue is fixed in version 0.65.0.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-116696 since 10/26/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1499.

Upgrading to version 0.65.0 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• Eugeny

Name

• russh

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26
• 0.27
• 0.28
• 0.29
• 0.30
• 0.31
• 0.32
• 0.33
• 0.34
• 0.35
• 0.36
• 0.37
• 0.38
• 0.39
• 0.40
• 0.41
• 0.42
• 0.43
• 0.44
• 0.45
• 0.46
• 0.47
• 0.48
• 0.49
• 0.50
• 0.51
• 0.52
• 0.53
• 0.54
• 0.55
• 0.56
• 0.57
• 0.58
• 0.59
• 0.60
• 0.61
• 0.62
• 0.63
• 0.64

Website

• Product: https://github.com/Eugeny/russh/

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