CVE-2026-77518: Auth Bypass (CVSS 5)

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.

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CVSS v3.1 Score

5.0

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

EPSS — Exploit Prediction

0.0027

Probability of exploitation

0.18%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-862 Missing Authorization

References

Other References

https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-x65c-w438-c58f

Frequently Asked Questions

What is CVE-2026-77518? +

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. It has a CVSS v3.1 base score of 5.0 (MEDIUM).

How severe is CVE-2026-77518? +

CVE-2026-77518 has a CVSS v3.1 score of 5.0 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0027, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-77518? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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