SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-103758

Obot 0.21.1 through 0.24.1 contains an authorization bypass vulnerability that allows authenticated users to reach MCP servers because the checkUI deny list omits the /mcp-connect-composite/ route.

HIGH 8.6EPSS 0.22%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.22%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Obot 0.21.1 through 0.24.1 contains an authorization bypass vulnerability that allows authenticated users to reach MCP servers because the checkUI deny list omits the /mcp-connect-composite/ route. Basic-role users with a composite MCP ID can proxy requests through mcpGateway.Proxy to invoke tools on MCP servers restricted by Access Control Rules.

CVSS 4.0
8.6 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/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/M
EPSS
0.22% probability · 13th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-863
Source
disclosure@vulncheck.com
EPSS trend
0%3%5%2 October 2026: 0.22%27 October 2026: 0.22%2 October 202627 October 2026

EPSS moved from 0.2% on 2 October 2026 to 0.2% on 27 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.