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Fencer Intel
medium 4.3

CVE-2026-111061 json

russh agent server converts constraint records into unbounded never-rolled-back tasks

published 21d ago modified 21d ago also EUVD-2026-104457 , GHSA-4wc5-f2rc-q74m

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 28%
public exploits
0
none known

Summary

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.

Patch / fix

  • crates.io russh 0.64.1
  • warpgate_project warpgate 0.64.1
  • russh_project russh 0.64.1
  • rust-russh Debian 14 0.64.1-1

debian advisories DEBIAN-CVE-2026-111061

Is CVE-2026-111061 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-111061 updated cvss 4.3

russh: russh: Denial of Service via resource exhaustion in SSH agent

  • Red Hat Hardened Images openshell 0.1.5-0.1.hum1, openshell 0.1.6-0.1.hum1, openshell-gateway 0.1.5-0.1.hum1, openshell-gateway 0.1.6-0.1.hum1, python3-openshell 0.1.5-0.1.hum1, python3-openshell 0.1.6-0.1.hum1
    fixed: vendor fix RHSA-2026:90366

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
21d ago

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/Eugeny/russh/security/advisories/GHSA-4wc5-f2rc-q74m referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.3 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
GitHub 3.1 4.3 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem package affected fixed in
crates.io russh
<0.64.1
0.64.1

Affected products

  • Eugeny russh

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.