Langflow Remote Code Execution via Missing Authentication (CVE-2025-3248)

Historical catalog analysis: CISA added this entry on May 05, 2025. The entry reflects catalog information retrieved on August 31, 2026, not a snapshot archived on the inclusion date. Check current vendor guidance before acting.

What the vulnerability is

CVE-2025-3248 is a missing authentication vulnerability (CWE-306) identified in Langflow. The flaw exists at the /api/v1/validate/code endpoint. Because this endpoint does not require authentication, a remote attacker can send crafted HTTP requests to execute arbitrary code on the host system.

Exposure and applicability

This vulnerability applies to deployments of Langflow that expose the affected API endpoint to untrusted networks. The risk is elevated for organizations utilizing Langflow in cloud environments or as part of an open-source pipeline where the management interface is accessible without a perimeter security layer. CISA has noted that this vulnerability has been utilized by known ransomware campaigns, indicating high exploitability in the wild.

Remediation priorities

Based on the reported exploitation status and the nature of the flaw, we analyze the following prioritization for defenders:

1. Immediate Patching or Mitigation: Priority should be given to applying vendor-supplied mitigations. If a patch is unavailable or cannot be applied immediately, the product may need to be discontinued to eliminate the exposure.
2. Network Isolation: For systems where patching is delayed, restricting access to the /api/v1/validate/code endpoint via network firewalls or API gateways could reduce the likelihood of remote exploitation by limiting the attacker’s reach.
3. Cloud Configuration Review: Organizations using Langflow as a cloud service should review their configurations against BOD 22-01 guidance to ensure that administrative endpoints are not inadvertently exposed to the public internet.

How to validate remediation

Verification must go beyond checking software version numbers, as a deployed version does not inherently guarantee that authentication is active and correctly configured on the specific endpoint.

Defenders should verify remediation by attempting to access the /api/v1/validate/code endpoint without providing credentials. A successful mitigation is evidenced when the system rejects unauthenticated requests with an appropriate error (e.g., 401 Unauthorized or 403 Forbidden) rather than processing the request. Validation should be performed in a controlled environment or during a maintenance window to ensure that the authentication requirement is strictly enforced at the API level.

Limits and open questions

While applying vendor mitigations reduces risk, residual risk remains if other unauthenticated endpoints exist or if the authentication mechanism itself contains flaws. It remains unknown exactly which versions of Langflow are affected, as the source focuses on the endpoint rather than a specific version range. Furthermore, while network isolation can limit access, it does not fix the underlying vulnerability; an attacker who has already gained internal network access could still exploit the flaw if the endpoint remains unauthenticated.

Source and editorial note

CVE-2025-3248: Langflow Missing Authentication Vulnerability · Source date: May 05, 2025 · Retrieved August 31, 2026.

Material facts are tied to the cited primary source. Recommendations are independent defensive analysis unless attributed to the source. Confirm consequential decisions against current authoritative guidance.

Archive date: May 08, 2025. The displayed post date is assigned three days after the source date to organize this retrospective archive; it does not mean this site published the analysis then. First published by this site: October 16, 2026 at 00:11 UTC.

Request a Vulnerability Assessment