BishopFox Sliver up to 1.7.3 Signed Message null pointer dereference

Summaryinfo

A vulnerability was found in BishopFox Sliver up to 1.7.3 and classified as problematic. Affected by this vulnerability is an unknown functionality of the component Signed Message Handler. The manipulation results in null pointer dereference. This vulnerability was named CVE-2026-29781. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability classified as problematic has been found in BishopFox Sliver up to 1.7.3. Affected is an unknown code of the component Signed Message Handler. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-29781 since 03/04/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. There are neither technical details nor an exploit publicly available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• BishopFox

Name

• Sliver

Version

• 1.7.0
• 1.7.1
• 1.7.2
• 1.7.3

Website

• Product: https://github.com/BishopFox/sliver/

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