CVE-2026-35388 | OpenSSH up to 10.2 Proxy-mode Multiplexing Session unprotected alternate channel

VDB-354961 · CVE-2026-35388 · GCVE-0-2026-35388 OPENSSH UP TO 10.2 PROXY-MODE MULTIPLEXING SESSION UNPROTECTED ALTERNATE CHANNEL HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 2.4 $0-$5k 0.85+ Summaryinfo A vulnerability was found in OpenSSH up to 10.2. It has been classified as problematic. This affects an unknown part of the component Proxy-mode Multiplexing Session Handler. This manipulation causes unprotected alternate channel. This vulnerability is handled as CVE-2026-35388. It is possible to launch the attack on the local host. There is not any exploit available. Upgrading the affected component is recommended. Detailsinfo A vulnerability classified as problematic was found in OpenSSH up to 10.2. Affected by this vulnerability is an unknown code block of the component Proxy-mode Multiplexing Session Handler. The manipulation with an unknown input leads to a unprotected alternate channel vulnerability. The CWE definition for the vulnerability is CWE-420. The product protects a primary channel, but it does not use the same level of protection for an alternate channel. As an impact it is known to affect integrity. The summary by CVE is: OpenSSH before 10.3 omits connection multiplexing confirmation for proxy-mode multiplexing sessions. The advisory is shared at openssh.org. This vulnerability is known as CVE-2026-35388 since 04/02/2026. The exploitation appears to be difficult. An attack has to be approached locally. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/02/2026). Upgrading to version 10.3 eliminates this vulnerability. Productinfo Type Connectivity Software Name OpenSSH Version 10.0 10.1 10.2 License open-source CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 2.5 VulDB Meta Temp Score: 2.4 VulDB Base Score: 2.5 VulDB Temp Score: 2.4 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 2.5 CNA Vector (MITRE): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Unprotected alternate channel CWE: CWE-420 / CWE-419 CAPEC: 🔒 ATT&CK: 🔒 Physical: Partially Local: Yes Remote: Partially Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: OpenSSH 10.3 Timelineinfo 04/02/2026 Advisory disclosed 04/02/2026 +0 days CVE reserved 04/02/2026 +0 days VulDB entry created 04/02/2026 +0 days VulDB entry last update Sourcesinfo Advisory: openssh.org Status: Confirmed CVE: CVE-2026-35388 (🔒) GCVE (CVE): GCVE-0-2026-35388 GCVE (VulDB): GCVE-100-354961 Entryinfo Created: 04/02/2026 19:38 Changes: 04/02/2026 19:38 (63) Complete: 🔍 Cache ID: 99:C6E:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸