Sliver is Vulnerable to Authenticated Nil-Pointer Dereference through its Handlers

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

2.1 · 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 · score source

EPSS

• CVE-2026-29781: 0.57% estimated exploitation activity in the next 30 days; percentile 47.12 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

1. Executive Summary 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. 2. Vulnerability Details 2.0 Technical Workflow: From Envelope to Handler Sliver encapsulates all C2 traffic in a generic sliverpb.Envelope, which acts as a routing wrapper. When the server receives an Envelope with Type = 53 (MsgBeaconRegister), the internal router strips the…

Published by the source

5 Mar 2026, 00:26 UTC

Last modified by the source

9 Mar 2026, 15:49 UTC

Source last checked

26 Oct 2026, 15:15 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-hx52-cv84-jr5v

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# Patch Next advisory brief: CVE-2026-29781

Advisory: Sliver is Vulnerable to Authenticated Nil-Pointer Dereference through its Handlers
IDs: CVE-2026-29781, GHSA-hx52-cv84-jr5v
Record: https://patchnext.com/advisories/cve-2026-29781 (revision 1, source checked 26 Oct 2026, 15:15 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/bishopfox/sliver: affected <= 1.7.3

## Suggested inspection (read-only)
- Go github.com/bishopfox/sliver: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/bishopfox/sliver.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-hx52-cv84-jr5v (GitHub-reviewed advisory GHSA-hx52-cv84-jr5v lists affected ranges: Go github.com/bishopfox/sliver >=0 <=1.7.3)

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