low3.7
CVE-2026-102822
russh: negotiating a MAC-requiring block cipher (CTR/CBC) with mac=none causes a slice-index-out-of-range panic
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rust | russh | <= 0.63.0 | 0.63.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-p8qx-h547-fjw9
- https://github.com/Eugeny/russh/security/advisories/GHSA-p8qx-h547-fjw9
- https://nvd.nist.gov/vuln/detail/CVE-2026-102822
- https://github.com/Eugeny/russh/commit/2885385abfee279092a41d80c6cb6ac367353159
- https://github.com/Eugeny/russh/releases/tag/v0.63.1