Critical severity · published Jun 30, 2026
CVE-2026-7663
Unauthenticated Cross-User MCP Resource Access and Tool Execution via Streamable Transport Authorization Bypass
9.8
CVSS
0.5%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 44% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LO
Langflow OSS · IBM
1.0.0 through 1.9.6 · source: vendor
LA
Langflow · Langflow
1.0.0 before 1.10.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-7663
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-7663
Vendor Advisory
https://www.ibm.com/support/pages/node/7277570
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