CVE-2026-29781: Sliver is a command and control framework that uses a custom Wireguard netstack. In versions from 1.7.3 and prior, a vulnerability exists in the Slive...

Description

Sliver is a command and control framework that uses a custom Wireguard netstack. In versions from 1.7.3 and prior, a vulnerability exists in the Sliver C2 server's Protobuf unmarshalling logic due to a systemic lack of nil-pointer validation. By extracting valid implant credentials and omitting nested fields in a signed message, an authenticated actor can trigger an unhandled runtime panic. Because the mTLS, WireGuard, and DNS transport layers lack the panic recovery middleware present in the HTTP transport, this results in a global process termination. While requiring post-authentication access (a captured implant), this flaw effectively acts as an infrastructure "kill-switch," instantly severing all active sessions across the entire fleet and requiring a manual server restart to restore operations. At time of publication, there are no publicly available patches.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS 4.0

2.1/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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

EPSS Probability

0.50%

39.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-476

Affected Software

Vendor	Product	Versions
Bishopfox	Sliver	<= 1.7.3

References

https://github.com/BishopFox/sliver/security/advisories/GHSA-hx52-cv84-jr5vExploit, Mitigation, Vendor Advisory

Timeline

Published: Mar 7, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-29781?

Sliver is a command and control framework that uses a custom Wireguard netstack. In versions from 1.7.3 and prior, a vulnerability exists in the Sliver C2 server's Protobuf unmarshalling logic due to a systemic lack of nil-pointer validation. By extracting valid implant credentials and omitting nested fields in a signed message, an authenticated actor can trigger an unhandled runtime panic. Because the mTLS, WireGuard, and DNS transport layers lack the panic recovery middleware present in the HTTP transport, this results in a global process termination. While requiring post-authentication access (a captured implant), this flaw effectively acts as an infrastructure "kill-switch," instantly severing all active sessions across the entire fleet and requiring a manual server restart to restore operations. At time of publication, there are no publicly available patches.

How severe is CVE-2026-29781?

CVE-2026-29781 has a CVSS score of 2.1/10 (LOW severity). The EPSS model estimates a 0.50% probability of exploitation in the next 30 days.

How do I fix CVE-2026-29781?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.