Bug 2562394 (CVE-2026-116696)

Summary:	CVE-2026-116696 russh: russh: Denial of Service via uncontrolled memory consumption in SSH agent
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in russh. This vulnerability can lead to a Denial of Service (DoS) due to unbounded memory consumption in the SSH agent service. A local process or a remote user with access to a forwarded agent socket can repeatedly submit keys containing an excessive number of confirmation constraint records. Because the agent stores these records without enforcing memory or count limits, memory usage grows continuously for the lifetime of the process, potentially exhausting system resources.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
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Description OSIDB Bzimport 2026-10-27 20:22:08 UTC

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.