# A russh SSH server accepts a publickey authentication whose signature uses a different algorithm than the one named in the request

Advisory record · `GHSA-j7h2-66j4-ghjf`

- **Identifiers:** `GHSA-j7h2-66j4-ghjf` · `CVE-2026-111062`
- **State:** Confirmed
- **Severity:** CVSS 2.3 Low
- **Critical:** No
- **Weakness (CWE):** [CWE-347](https://cwe.mitre.org/data/definitions/347.html)
- **Tags:** [Weak cryptography or TLS](https://agentprime.io/advisories/tag/weak-crypto.md)
- **Published:** 19 Oct 2026
- **Updated:** 19 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 19 Oct 2026, 17:06 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `russh` (crates.io): affected `>=0.34.0-beta.1, <0.64.0`; fixed in `0.64.0`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> russh versions from 0.34.0-beta.1 before 0.64.0 do not check that a publickey signature's algorithm matches the one named in the authentication request. A client holding a valid RSA key can get a SHA-1 signature accepted by a server that is set to refuse SHA-1. Upgrade to russh 0.64.0.

Written 3 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 2.3 Low, CVSS 4.0: `CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** No score.

## Timeline

- 31 Oct 2026, 14:24 UTC: First seen by agentprime
- 31 Oct 2026, 14:24 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-j7h2-66j4-ghjf)
- 5 Nov 2026, 20:47 UTC: [Confirmed by the CVE List](https://www.cve.org/CVERecord?id=CVE-2026-111062)
- 5 Nov 2026, 21:18 UTC: [Confirmed by NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-111062)

## Sources

- [GitHub Advisory Database: GHSA-j7h2-66j4-ghjf](https://github.com/advisories/GHSA-j7h2-66j4-ghjf)
- [OSV: GHSA-j7h2-66j4-ghjf](https://osv.dev/vulnerability/GHSA-j7h2-66j4-ghjf)
- <https://github.com/Eugeny/russh/security/advisories/GHSA-j7h2-66j4-ghjf>
- <https://github.com/Eugeny/russh/commit/a0ded76bdc352f8fbeaaeb175fb2a0c586fbc8f2>
- <https://github.com/Eugeny/russh>
- <https://github.com/Eugeny/russh/releases/tag/v0.64.0>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-j7h2-66j4-ghjf>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-j7h2-66j4-ghjf/>. Everything for agents: <https://agentprime.io/llms.txt>.