CVE-2026-35388: CWE-420 Unprotected Alternate Channel in OpenBSD OpenSSH
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. There are no known exploits in the wild, and no official patch or vendor advisory is currently provided.
AI Analysis
Technical Summary
OpenSSH prior to version 10.3 fails to confirm connection multiplexing for proxy-mode multiplexing sessions, resulting in an unprotected alternate channel as identified by CWE-420. This omission could allow an attacker with local access to initiate multiplexed connections without proper verification, potentially leading to limited integrity impacts. The CVSS 3.1 base score is 2.5, reflecting low severity with attack vector local, high attack complexity, no privileges required, and user interaction required. No patch or official remediation guidance is currently available.
Potential Impact
The vulnerability may allow an attacker with local access and user interaction to exploit an unprotected alternate channel in OpenSSH multiplexing proxy mode, causing limited integrity impact. There is no impact on confidentiality or availability. No known exploits have been reported in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the OpenBSD vendor advisory for current remediation guidance. Until an official fix is released, users should consider avoiding proxy-mode multiplexing sessions or restrict local access to trusted users to reduce risk.
CVE-2026-35388: CWE-420 Unprotected Alternate Channel in OpenBSD OpenSSH
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. There are no known exploits in the wild, and no official patch or vendor advisory is currently provided.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
OpenSSH prior to version 10.3 fails to confirm connection multiplexing for proxy-mode multiplexing sessions, resulting in an unprotected alternate channel as identified by CWE-420. This omission could allow an attacker with local access to initiate multiplexed connections without proper verification, potentially leading to limited integrity impacts. The CVSS 3.1 base score is 2.5, reflecting low severity with attack vector local, high attack complexity, no privileges required, and user interaction required. No patch or official remediation guidance is currently available.
Potential Impact
The vulnerability may allow an attacker with local access and user interaction to exploit an unprotected alternate channel in OpenSSH multiplexing proxy mode, causing limited integrity impact. There is no impact on confidentiality or availability. No known exploits have been reported in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the OpenBSD vendor advisory for current remediation guidance. Until an official fix is released, users should consider avoiding proxy-mode multiplexing sessions or restrict local access to trusted users to reduce risk.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-04-02T16:57:30.433Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 69cea282e6bfc5ba1ded3a61
Added to database: 4/2/2026, 5:08:18 PM
Last enriched: 4/9/2026, 11:58:53 PM
Last updated: 5/20/2026, 8:51:59 PM
Views: 55
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.