Vulnerability in russh (CVE-2026-68930)
Summary
Vulnerability in russh (CVE-2026-68930). Data can be tampered with by attackers. Exploitable via russh. Mitigation: upgrade to 0.62.5 or later.
Original description
The description as published by the source.
There is a server-side channel state issue in russh.
After a client is authenticated, russh can dispatch channel-scoped handler callbacks for recipient channel IDs that were never opened or confirmed. In the strongest reproduced case, the client does not send SSH_MSG_CHANNEL_OPEN at all. It authenticates normally, then sends SSH_MSG_CHANNEL_REQUEST packets with request type exec for a range of recipient channel IDs. russh still calls the server application's exec_request handler.
This is not an authentication bypass. A valid login is required. The issue is that the SSH channel lifecycle is not enforced before channel-scoped callbacks are delivered to the application.
Impact
An authenticated client can bypass the server application's channel-open policy.
A server may deny session channels by returning false from Handler::channel_open_session. A server may also assume that callbacks such as exec_request, shell_request, subsystem_request, data, channel_eof, or channel_close are only delivered for channels that were opened and confirmed by the SSH transport layer.
That assumption does not hold in the vulnerable path. A malicious authenticated peer can send channel-scoped messages for arbitrary recipient channel IDs and cause handler callbacks to run even though no channel exists.
The exact impact depends on the downstream application. For many SSH server use cases, exec_request, shell_request, or subsystem_request start commands, jobs…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-68930 has been found in russh.
Attackers can target a specific entry point like russh over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 6.5/10.
What to do: upgrade russh to 0.62.5 or later.
If unsure, ask your IT team or search "russh CVE-2026-68930" on the vendor's site.
CVE-2026-68930 (russh) — CWE-666 / CVSS v3 6.5
Attack vector: remote (network-reachable) / no user interaction
Attack surface: russh / SSH_MSG_CHANNEL_OPEN / SSH_MSG_CHANNEL_REQUEST / exec
Patched: 0.62.5 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-666) exists in russh. Attackers reach the vulnerable code path via russh.
Check the vendor advisory for the affected versions of russh. Attack surface: russh / SSH_MSG_CHANNEL_OPEN / SSH_MSG_CHANNEL_REQUEST / exec.
Severity: Medium (CVSS 6.5/10). Data can be tampered with by attackers.
Update to 0.62.5.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'russh' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'russh' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
russhを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade russh to 0.62.5ステージング環境で 0.62.5 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。