MaxKB: Missing per-tool authorization in the agent and workflow tool-dispatch path

published 2026-09-21 48 d ago modified 2026-09-28 41 d ago also EUVD-2026-84157

cvss: 5.4; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits: 0; none known

MaxKB is an open-source AI assistant for enterprise. From version 2.0.0 through 2.9.2, a lowest-role workspace member denied access to a tool by WorkspaceUserResourcePermission can still bind its identifier through tool_ids, skill_tool_ids, or mcp_tool_ids and execute it through the agent or workflow dispatch path. The dispatch path does not reapply the per-tool grant enforced by dedicated tool routes, and tool execution decrypts server-side init_params, allowing the caller to receive credentials carried by the denied tool. No fixed version is available as of this review.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 41 d ago (2026-09-28)

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-383v-fx78-pphm referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Affected products

1Panel-dev MaxKB

Classification

Weakness

CWE-639 Authorization Bypass Through User-Controlled Key
CWE-862 Missing Authorization

References

github.com /1Panel-dev/MaxKB/security/advisories/GHSA-383v-fx78-pphm
exploit

Sources

CVE List CVE-2026-77516
NVD CVE-2026-77516

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary