CVE-2026-128088: russh try_sign · asynchronous confirmation can sign after agent lock
Affects russhSource GCVE Database
Not known to be exploited · CVSS 2.2 Low : upgrade to 0.65.1 when convenient.
Data as of 13 Nov 2026, 20:19 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 2.2 |
|---|
- Patch
- Available – fixed in 0.65.1
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 13 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Upgrade russh to 0.65.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| crates.iorussh | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in russh version 0.65.1 that addresses this TOCTOU vulnerability by ensuring the agent's lock state is revalidated after asynchronous confirmation before signing. Users should upgrade to version 0.65.1 or later to remediate this issue. No additional mitigations are indicated by the vendor advisory.
Description
In russh version 0.65.0, a time-of-check to time-of-use (TOCTOU) vulnerability exists in the agent's asynchronous confirmation process. A sign request for a confirmation-constrained key can complete signing after the agent has been locked by another connection, bypassing the lock state. This occurs because the private key is cloned and held across an await point without revalidating the lock state after confirmation. The flaw violates RFC 9987 section 5.7, which requires suspending private-key signature operations while the agent is locked. The issue is fixed in version 0.65.1.
References
- github.com/Eugeny/russh/security/advisories/GHSA-736f-c93q-9fwx (opens in a new tab)
- github.com/Eugeny/russh/pull/808 (opens in a new tab)
- github.com/Eugeny/russh/commit/43a46d67a80a7355fcd2fb25e7e00d79aec8184c (opens in a new tab)
- github.com/Eugeny/russh (opens in a new tab)
- github.com/Eugeny/russh/releases/tag/v0.65.1 (opens in a new tab)