The Claude Desktop app gives you Claude Code with a graphical interface built for running multiple sessions side by side. From 1.2581.0 to before 1.4304.0, Claude Desktop's SSH remote development feature verified only whether a hostname existed in ~/.ssh/known_hosts without comparing the server's presented host key against the stored key. This allowed a network-positioned attacker to present an arbitrary SSH host key and have the connection silently accepted, enabling a man-in-the-middle attack on remote development sessions. Successful exploitation required the attacker to be in a network position to intercept SSH traffic (e.g., via ARP spoofing, rogue Wi-Fi, or DNS poisoning) and the target hostname to already have an entry in the victim's known_hosts file. This vulnerability is fixed in 1.4304.0.
https://github.com/anthropics/claude-code/security/advisories/GHSA-3rwf-2g6p-c2f9
Published: 2026-05-13
Updated: 2026-05-13
Base Score: 4.3
Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N
Severity: Medium
Base Score: 7.4
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Severity: High
Base Score: 7.4
Vector: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00016