Resource exhaustion in Eugeny Russh
CVE-2026-111061
russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. Prior to 0.64.1, the agent server spawns a separate long-lived task for every SSH_AGENT_CONSTRAIN_LIFETIME record in a constrained add-key request. The loop accepts repeated lifetime records, clones the key blob into each task, and does not roll back tasks when later constraint parsing fails. An attacker that can speak the agent protocol locally or through agent forwarding can exhaust memory and tasks until the agent process is starved or terminated, denying SSH agent service. This issue is fixed in version 0.64.1.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Eugeny Russh — versions < 0.64.1
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-111061?
- CVE-2026-111061 is a medium-severity vulnerability in Eugeny Russh, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 4.3/10. Published 2026-10-19.
- How severe is CVE-2026-111061?
- Medium severity. CVSS v3 base score is 4.3 out of 10.