CVE-2026-48108 PUBLISHED

Russh: SSH identification parsing accepted non-canonical client banners and did not bound pre-banner input

Assigner: GitHub_M
Reserved: 20.05.2026 Published: 10.06.2026 Updated: 11.06.2026

Russh is a Rust SSH client & server library. From version 0.34.0-beta.1 to before version 0.61.0, russh did not enforce the SSH identification-string rules as deliberately as OpenSSH. In particular, the server-side identification reader used the same permissive path as the client, allowing pre-banner lines from clients, and the reader did not enforce a bounded number of pre-banner lines. For a library server built on russh, this could allow a remote peer to hold connection setup resources in the cleartext pre-authentication phase with malformed identification input that should have been rejected early. This issue has been patched in version 0.61.0.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS Score: 5.3

Product Status

Vendor Eugeny
Product russh
Versions
  • Version >= 0.34.0-beta.1, < 0.61.0 is affected

References

Problem Types

  • CWE-20: Improper Input Validation CWE