5

CVE-2026-77518: MaxKB: Known MCP tool IDs expose owner Tool.code and can be referenced by attacker workflows

Deferred
Published 21-09-2026Last modified 22-09-2026

Vulnerability summary

CVE-2026-77518 is a medium (CVSS 5.0) Missing Authorization vulnerability in 1panel-dev maxkb. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 19.3% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.0/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.27%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 21-09-2026
    PublishedVulnerability first disclosed.
  2. 22-09-2026
    Last modifiedVulnerability information updated.

Description

MaxKB is an open-source AI assistant for enterprise. In 2.10.2-lts and earlier, a normal workspace user who knows another user's active MCP tool_id in the same workspace can retrieve the hidden tool through the tool-detail route because it does not apply the per-resource authorization used by the list route. The response includes Tool.code, which may contain MCP server configuration and headers, and an attacker who can create or edit an attacker-owned workflow can place the same foreign mcp_tool_id in a workflow mcp-node so workflow debug uses the owner's MCP configuration without verifying permission to use that tool. No fixed version is available as of this review.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.27%

Chance of exploitation in the next 30 days

Percentile

19%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.27% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

1panel-dev1 product

1 vendor · 1 product

References

1 links