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TI-2026-35548 Aliases CVE-2026-48108GHSA-76r6-x97p-67vr

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

Priority MEDIUM 63CWE-20Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00277 20th percentileScored 2026-11-07
Fix Fixed russh (Eugeny): 0.61.0russh (crates.io): 0.61.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Eugenyrussh0.34.0-beta.1 to before 0.61.00.61.0Patch availableCNA
—russh (crates.io)0.34.0-beta.1 to before 0.61.00.61.0Patch availableGHSA-76r6-x97p-67vr
  • russh VendorEugeny Affected 0.34.0-beta.1 to before 0.61.0 Fixed in 0.61.0 Patch available CNA
  • russh (crates.io) Vendor— Affected 0.34.0-beta.1 to before 0.61.0 Fixed in 0.61.0 Patch available GHSA-76r6-x97p-67vr

Remediation

  • Fix · CNA russh (Eugeny) Fixed in 0.61.0
  • Fix · GHSA-76r6-x97p-67vr russh (crates.io) Fixed in 0.61.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-48108
  2. 2026-10-03 Alias added: GHSA-76r6-x97p-67vr

References

Advisory 1

Other 2

  • TI-2026-65512 russh: Client-side channel-scoped Handler callbacks fire for channel IDs the client never opened CVSS 3.1HIGH 7.5
  • TI-2026-35550 Russh: SSH message fields were decoded through allocation-first parsers before field-specific bounds CVSS 3.1HIGH 7.5
  • TI-2026-34331 Russh: Post-decompression SSH packet size was not bounded, allowing remote oversized compressed packets CVSS 3.1HIGH 7.5
  • TI-2026-34308 Resource allocation without limits in Eugeny russh CVSS 3.1HIGH 7.5
  • TI-2025-16084 Tabby has a TCC Bypass via Misconfigured Node Fuses CVSS 4.0HIGH 8.6
  • TI-2024-36991 Tabby has a TCC Bypass via Unnecessary Permissive Entitlements in Tabby CVSS 4.0HIGH 8.6
See all 25 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences