NullHub: Missing authentication in management API
Summary
NullHub, a management console for nullclaw AI agent instances, does not enforce authentication on its /api/* management API because the auth_token defaults to null and is never set. An unauthenticated attacker who can reach a non-loopback listener can control agent instances, rewrite configurations including provider credentials, and manage cron jobs and MCP servers. The CVSS 4.0 score is 9.2 and the vulnerability is network-reachable without privileges or user interaction.
Affected
- NullHub through 2026.5.29
- Default configuration is unaffected according to the CVE record; the issue applies to non-loopback listeners
Fixed in
- Unknown. No released fixed version has been identified; a fixed commit is referenced in OSV (c6b4dab2fca5d6e0c25959fb1cdd6ab1d0d1278f).
Workaround
- Bind NullHub to loopback only and reach it through an SSH tunnel or an authenticating reverse proxy
- Isolate affected NullHub instances until a vendor update is available
- Monitor logs for API requests without Authorization or Origin headers
Exploitation
- CISA SSVC: exploitation status poc, automatable: no, technical impact: total
- Not marked as known exploited (KEV)
- No public exploit confirmed in the sources reviewed
Our recommendation
- Inventory all NullHub and nullclaw deployments
- Restrict the management port to loopback or VPN access and do not expose it to the internet
- Rotate provider credentials if an exposed instance may have been reached
- Track the vendor repository for a fixed release and update promptly
- Monitor logs for unauthenticated API requests
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- NullHub repository github.com
- NullHub Dockerfile at v2026.5.29 github.com
- NullHub settings API at v2026.5.29 github.com
- NullHub server at v2026.5.29 github.com
- VulnCheck advisory www.vulncheck.com
- OSV entry CVE-2026-110616 osv.dev
- Kernel Weekly report kernelweekly.com
- Third-party issue agent-audit-kit #997 github.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 04:36.
Original description (NVD)
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.
NVD references (7)
- https://github.com/nullclaw/nullhub
- https://github.com/nullclaw/nullhub/blob/v2026.5.29/Dockerfile#L69-L71
- https://github.com/nullclaw/nullhub/blob/v2026.5.29/src/api/settings.zig#L29-L54
- https://github.com/nullclaw/nullhub/blob/v2026.5.29/src/server.zig#L546-L556
- https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/rJrLma3izg
- https://www.vulncheck.com/advisories/nullhub-through-2026.5.29-missing-authentication-for-api-management-api
- https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/rJrLma3izg
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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