CVE-2026-13448 affects IBM Langflow OSS versions 1.0.0 through 1.10.1. The vulnerability is an unauthenticated remote code execution flaw located in the /api/v1/build_public_tmp/{flow_id}/flow endpoint. It results from an incomplete denylist in the validate_public_flow_no_code_execution() function, which does not block several code-execution agent components such as OpenDsStarAgent, CodeActAgentSmolagents, and CSVAgent. This allows an attacker to execute arbitrary code remotely without authentication. The CVSS 3.1 base score is 8.1, indicating high severity. There is no vendor advisory or patch available at this time, and no known exploits in the wild have been reported.

Successful exploitation of this vulnerability could allow an unauthenticated attacker to execute arbitrary code remotely on affected IBM Langflow OSS instances. This could lead to full compromise of the affected system, including confidentiality, integrity, and availability impacts.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict access to the vulnerable endpoint and monitor for suspicious activity related to the public flow build endpoint. Avoid exposing the affected versions to untrusted networks.