# CVE-2026-21445: Langflow - Authentication Bypass

> Live exploitation tracking for CVE-2026-21445 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2026-21445

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 8.8
- **Public exploit available:** Yes
- **Affected products:** Langflow
- **Weaknesses:** CWE-306 (Missing Authentication for Critical Function)
- **Tags:** ai_mcp, web_application

## Description

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.7.0.dev45, multiple critical API endpoints in Langflow are missing authentication controls. The issue allows any unauthenticated user to access sensitive user conversation data, transaction histories, and perform destructive operations including message deletion. This affects endpoints handling personal data and system operations that should require proper authorization. Version 1.7.0.dev45 contains a patch.

## CrowdSec analysis

[CVE-2026-21445](https://euvd.enisa.europa.eu/vulnerability/CVE-2026-21445) is a critical authentication bypass vulnerability in Langflow, a platform for building and deploying AI-powered agents and workflows. This flaw allows unauthenticated attackers to access sensitive user conversation data, transaction histories, and perform destructive actions such as message deletion via unprotected API endpoints. Exploitation of this vulnerability could lead to significant data breaches and unauthorized manipulation of user or system data. Upgrading to version 1.7.0.dev45 is strongly recommended to mitigate these risks.

CrowdSec has been tracking this vulnerability and its exploits since 1st of April 2026.

CrowdSec network observations suggest that most exploitation of CVE-2026-21445 involves focused reconnaissance to identify viable targets. Attackers typically tailor their campaigns based on system exposure and configuration. It is unlikely that a given attack is accidental.
CrowdSec network telemetry also shows that exploitation of CVE-2026-21445 has significantly declined over the past week. Attack volumes are well below the long-term average, suggesting attackers are rapidly losing interest. The vulnerability appears to be falling out of active use across most threat landscapes.

Attackers exploit unauthenticated access to the `/api/v1/monitor/messages` endpoint to retrieve sensitive user conversation data and message histories without authorization.

## Timeline

- 2026-01-02: CVE Published. CVE-2026-21445 is published to NVD.
- 2026-04-01: Rule Released. CrowdSec releases a rule to detect CVE-2026-21445 exploitation attempts against the CrowdSec Network.
- 2026-04-09: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2026-21445 for the first time.

## References

- https://github.com/langflow-ai/langflow/security/advisories/GHSA-c5cp-vx83-jhqx
- https://github.com/langflow-ai/langflow/commit/3fed9fe1b5658f2c8656dbd73508e113a96e486a
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-21445.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2026-21445) follows observed exploitation activity for CVE-2026-21445. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.