Vulnerability in russh (CVE-2026-73489)
Summary
Vulnerability in russh (CVE-2026-73489). Risk of unauthorized operations or information disclosure. Exploitable via russh. Mitigation: upgrade to 0.61.0 or later.
Original description
The description as published by the source.
Summary
A post-authentication denial-of-service panic in russh 0.62.2 (commit
c4be19f1915c8682f4615c3fd50008512b474491, current default branch main as
of 2026-07-22). An authenticated client sends a pty-req channel request
carrying more than 130 terminal-mode records. The parser uses a fixed
[(Pty::TTY_OP_END, 0); 130] array but increments its counter i for every
valid record (logging "too many pty codes" without returning), then slices
&modes[0..i] — an out-of-bounds slice that panics (range end index 131 out of range for slice of length 130) before the application pty_request
handler runs.
This is reachable with the default server configuration and the default
crypto config (curve25519-sha256 + chacha20-poly1305), requiring only an
authenticated session channel — no caller-supplied parameter. It is reproduced
end-to-end against the unmodified real russh 0.62.2 library (a real
russh::client + russh::server over TCP, using the public
Channel::request_pty(...) API); the PoC below links the real crate, not a
copied snippet. The defect is still present on main HEAD (v0.62.3,
2026-07-22) and is not covered by any of the 11 published russh GHSA
advisories (GHSA-4r3c-5hpg-58qr / CVE-2026-48110 is allocation-first string
parsing, not the fixed-array slice overflow; it was fixed in 0.61.0 but this
code path still overflows the fixed array).
Rust bounds-checked panics abort the task safely (no memory corruption / RCE);
the impact is remote…
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-2026-73489 has been found in russh.
Attackers can target a specific entry point like russh over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 4.3/10.
What to do: upgrade russh to 0.61.0 or later.
If unsure, ask your IT team or search "russh CVE-2026-73489" on the vendor's site.
CVE-2026-73489 (russh) — CWE-129 / CVSS v3 4.3
Attack vector: remote (network-reachable) / no user interaction
Attack surface: russh / c4be19f1915c8682f4615c3fd50008512b474491 / main / pty_request
Patched: 0.61.0 — 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-129) exists in russh. Attackers reach the vulnerable code path via russh.
Check the vendor advisory for the affected versions of russh. Attack surface: russh / c4be19f1915c8682f4615c3fd50008512b474491 / main / pty_request.
Severity: Medium (CVSS 4.3/10). Risk of unauthorized operations or information disclosure.
Update to 0.61.0.
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 0.61.0ステージング環境で 0.61.0 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。