CVE-2026-34227: Sliver One-Click Remote Access: Insecure CORS & Unauthenticated MCP Interface

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-03-31 · updated 2026-07-24
Weakness: CWE-306

Description

Sliver is a command and control framework that uses a custom Wireguard netstack. Prior to version 1.7.4, a single click on a malicious link gives an unauthenticated attacker immediate, silent control over every active C2 session or beacon, capable of exfiltrating all collected target data (e.g. SSH keys, ntds.dit) or destroying the entire compromised infrastructure, entirely through the operator's own browser. This issue has been patched in version 1.7.4.

Affected products

BishopFox sliver: before 1.7.4 — fixed in 1.7.4

How to fix

Upgrade to a fixed version: BishopFox sliver 1.7.4. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-34227 or the next vulnerability affects your stack