Disclosure summary
Russh is a Rust SSH client and server library. Prior to 0.63.1, a connection configured to permit mac=none can negotiate it with a MAC-requiring CTR or CBC block cipher because the selection logic validates needs_mac() only when MAC selection fails. A remote peer can then send a packet with a decrypted length of zero, causing russh/src/cipher/mod.rs to shrink the previously read block before indexing buffer.buffer[16..], which panics and terminates the connection task. This issue is fixed in version 0.63.1.
Source-reported weakness categories
CWE-129
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
GitHub Reviewed Security Advisories · GHSA-p8qx-h547-fjw9
Open original source · Updated Sep 30, 2026
russh: negotiating a MAC-requiring block cipher (CTR/CBC) with mac=none causes a slice-index-out-of-range panic
Source severity: LOW / 0
| Ecosystem | Package | Affected range | First patched |
|---|---|---|---|
| rust | russh | 0.63.1 |
NIST National Vulnerability Database · NVD-CVE-2026-102822
Open original source · Updated Sep 29, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
Original records & references
PUBLISHED 2026-09-29T15:17:24-04:00
MODIFIED 2026-09-29T16:17:17-04:00
INGESTED 2026-10-06T11:43:05-04:00