CVE-2026-34227
published 2026-03-31CVE-2026-34227: 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…
PriorityP352high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
EPSS
0.40%
32.0th percentile
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
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| bishopfox | sliver | < 1.7.4 | 1.7.4 |
| github.com | bishopfox_sliver | >= 0 < 1.7.4 | 1.7.4 |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvdv4.05.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
ghsa5.9MEDIUM
osv5.9MEDIUM
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
GHSA
Sliver One-Click Remote Access: Insecure CORS & Unauthenticated MCP Interface
ghsa·2026-03-31·CVSS 5.9
CVE-2026-34227 [MEDIUM] CWE-306 Sliver One-Click Remote Access: Insecure CORS & Unauthenticated MCP Interface
Sliver One-Click Remote Access: Insecure CORS & Unauthenticated MCP Interface
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.
## Description
The Sliver MCP server runs inside the Sliver Client and binds an unauthenticated HTTP and SSE interface to `localhost:8080` by default. The service returns a permissive `Access-Control-Allow-Origin: *` header on all responses.
Because this server is client-side, the attack surface is distributed across every individual operator in the operation. Any arbitrary website can issue cross-origin
OSV
Sliver One-Click Remote Access: Insecure CORS & Unauthenticated MCP Interface
osv·2026-03-31·CVSS 5.9
CVE-2026-34227 [MEDIUM] Sliver One-Click Remote Access: Insecure CORS & Unauthenticated MCP Interface
Sliver One-Click Remote Access: Insecure CORS & Unauthenticated MCP Interface
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.
## Description
The Sliver MCP server runs inside the Sliver Client and binds an unauthenticated HTTP and SSE interface to `localhost:8080` by default. The service returns a permissive `Access-Control-Allow-Origin: *` header on all responses.
Because this server is client-side, the attack surface is distributed across every individual operator in the operation. Any arbitrary website can issue cross-origin
No detection rules found.
No public exploits indexed.
2026-03-31
Published