Evidence-led vulnerability intelligence · 2026-10-28 02:48 IST

CVE-2026-116696

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.

LOW · 3.3

Executive briefing

The source record describes: 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 practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.

Assessment: Potential exposure only — validate the installed product, exact version, configuration and vendor applicability before treating an asset as confirmed vulnerable.

Evidence confidence: Limited Evidence-derived, not an exploitability verdict

Severity & attack characteristics

3.3 / 10 · 3.1

CVSS vector:
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Attack vectorL

Attack complexityL

Privileges requiredL

User interactionN

ScopeU

Confidentiality impactN

Integrity impactN

Availability impactL

Technical explanation & impact

The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.

Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.

Weakness classification

CWE-770

Affected products and versions

NVD has not supplied machine-readable vulnerable CPE product/version entries for this CVE. This is an information gap, not proof that no products are affected. Check the vendor advisory references below.

Remediation & validation

Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
Validate the remediation with a version check and vulnerability rescan, then retain change evidence.

No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.

Vendor advisories, patches & exploit references

https://github.com/Eugeny/russh/commit/23aa5d28fe9601c5bdfe9e60b7ec5d4f882c3de6 VENDOR security-advisories@github.com
https://github.com/Eugeny/russh/releases/tag/v0.65.0 VENDOR security-advisories@github.com
https://github.com/Eugeny/russh/security/advisories/GHSA-9wfm-jcj8-jfv9 VENDOR security-advisories@github.com
https://github.com/Eugeny/russh/security/advisories/GHSA-9wfm-jcj8-jfv9 VENDOR 134c704f-9b21-4f2e-91b3-4a467353bcc0

Information gaps & confidence notes

These gaps indicate missing source data. CVE Watch does not fill them with guessed product, exploit or patch details.

NVD does not currently provide machine-readable vulnerable CPE product/version entries for this record.

Last enrichment: 2026-11-03T22:01:54+00:00 · Source last modified: 2026-11-02T20:17:33.387

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