CVE-2026-35388: OpenBSD OpenSSH · Unprotected Alternate Channel
Affects OpenBSD OpenSSHSource CVE Database V5
Not known to be exploited · CVSS 2.5 Low : upgrade to 10.3 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 10.3
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 2 Apr 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 30 Oct 2026.
What to do
Upgrade OpenBSD OpenSSH to 10.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| OpenBSDOpenSSH | Affected
| Fixed in
|
AI-suggested
If you cannot patch yet, users should consider avoiding proxy-mode multiplexing sessions or restrict local access to trusted users to reduce risk.
Description
CVE-2026-35388 is a low-severity vulnerability in OpenSSH versions before 10.3 where connection multiplexing confirmation is omitted for proxy-mode multiplexing sessions. This issue relates to CWE-420, an unprotected alternate channel, potentially allowing limited unauthorized interaction. The vulnerability does not impact confidentiality or availability but may cause limited integrity issues.