Low severity · published Oct 27, 2026
CVE-2026-116696
russh's SSH agent server is susceptible to unbound allocations via repeated SSH_AGENT_CONSTRAIN_CONFIRM messages
New
3.3
CVSS
0.1%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 1% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RU
russh · Eugeny
< 0.65.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-116696
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-116696
github.com
https://github.com/Eugeny/russh/commit/23aa5d28fe9601c5bdfe9e60b7ec5d4f882c3de6
github.com
https://github.com/Eugeny/russh/releases/tag/v0.65.0
github.com
https://github.com/Eugeny/russh/security/advisories/GHSA-9wfm-jcj8-jfv9
More from russh
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CVE-2026-48110
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7.5
CVE-2026-46702
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CVE-2026-46673
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