Description
NullHub through 2026.5.29 contains a missing authentication vulnerability that allows unauthenticated attackers to access the /api/* management API because the auth_token field defaults to null and is never assigned. Attackers sending requests without Authorization or Origin headers to non-loopback listeners can control agent instances, rewrite configurations including provider credentials, and manage cron jobs and MCP servers.
References7
- github.com/nullclaw/nullhub
- github.com/nullclaw/nullhub/blob/v2026.5.29/Dockerfile#L69-L71
- github.com/nullclaw/nullhub/blob/v2026.5.29/src/api/settings.zi…
- github.com/nullclaw/nullhub/blob/v2026.5.29/src/server.zig#L546…
- hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/rJrLma3izg
- www.vulncheck.com/advisories/nullhub-through-2026.5.29-missing-…
- hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/rJrLma3izg
Metrics
- CVSS 3.1
-
8.1
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 4.0
-
9.2
CRITICAL
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/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 - EPSS — exploit probability
- 1% percentile: 62 · as of 11 November 2026
- CWE
- CWE-306
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.