CVE-2026-7663CWE-285

Unauthenticated Cross-User MCP Resource Access and Tool Execution via Streamable Transport Authorization Bypass

Critical · published June 30, 2026

CVSS v3.1
9.1
EPSS
1%
Percentile
43.3
In the wild
Unconfirmed
What it is

IBM Langflow OSS 1.0.0 through 1.9.6 could allow unauthenticated attackers to access protected MCP project resources and execute MCP operations due to improper authorization enforcement in the Streamable MCP transport endpoint.

The record
Technical detail
CVSS v3.1
9.1 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00520 · 43.3th percentile
Weakness
CWE-285 · Improper Authorization
Published
2026-06-30T19:16Z
EPSS history
Timeline
  • 30 JUN 19:16Z
    Unauthenticated Cross-User MCP Resource Access and Tool Execution via Streamable Transport Authorization Bypass
    cvelistv5