CVE-2026-42189
Prior to version 0.60.1, a pre-authentication denial-of-service vulnerability exists in the server's keyboard-interactive authentication handler.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.48%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Russh is a Rust SSH client & server library. Prior to version 0.60.1, a pre-authentication denial-of-service vulnerability exists in the server's keyboard-interactive authentication handler. A malicious client can crash any russh-based server that implements keyboard-interactive auth (e.g., for 2FA/TOTP) with a single malformed packet, requiring no credentials. This issue has been patched in version 0.60.1.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.48% probability · 40th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-770, CWE-789
- Affected
- russh project/russh · warpgate project/warpgate
- Source
- security-advisories@github.com
References
- https://github.com/Eugeny/russh/commit/6c3c80a9b6d60763d6227d60fa8310e57172a4d1Patch
- https://github.com/Eugeny/russh/releases/tag/v0.60.1Product, Release Notes
- https://github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmgExploit, Mitigation, Vendor Advisory
- https://github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmgExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.