CVE-2026-116773
russh is a Rust SSH client and server library that includes an SSH agent protocol implementation.
Impact
russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. Prior to 0.65.0, the client Session::process_packet path in russh/src/client/encrypted.rs accepts repeated packets encoded with russh's private msg::EXT_INFO = 7 before authentication, while the standards-compliant EXT_INFO message number 82 does not reach the affected handler. The handle_ext_info function appends every parsed extension name to received_extensions without clearing, deduplicating, or bounding the vector. A malicious SSH server that deliberately sends private message number 7 can therefore retain an unbounded number of attacker-controlled extension names for the session lifetime, causing progressive client memory exhaustion. This issue is fixed in version 0.65.0.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rust | russh | < 0.65 | 0.65 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Eugeny | Russh | before 0.65.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-4p9f-7p9m-5vfg
- https://github.com/Eugeny/russh/security/advisories/GHSA-4p9f-7p9m-5vfg
- https://nvd.nist.gov/vuln/detail/CVE-2026-116773
- https://github.com/Eugeny/russh/commit/b33e93beec393e6d29eee69c1b8831736724ee75
- https://github.com/Eugeny/russh/releases/tag/v0.65.0