Russh: Unchecked keyboard-interactive prompt count in client auth path
CVE-2026-48107

6.5MEDIUM

Key Information:

Vendor

Eugeny

Status
Russh
Vendor
CVE Published:
10 June 2026

What is CVE-2026-48107?

Russh is a Rust SSH client & server library. From version 0.37.0 to before version 0.61.0, in the russh client keyboard-interactive authentication path, a malicious SSH server could send a USERAUTH_INFO_REQUEST with an attacker-controlled prompt count, and the client would use that raw count directly in Vec::with_capacity(...) before validating that enough prompt data was actually present in the packet. This issue has been patched in version 0.61.0.

Affected Version(s)

russh >= 0.37.0, < 0.61.0

References

https://github.com/Eugeny/russh/security/advisories/GHSA-...
x_refsource_CONFIRM

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.