Langflow - RCE (CVE-2025-34291)
Description
Langflow versions up to and including 1.6.9 contain a chained vulnerability that enables account takeover and remote code execution. An overly permissive CORS configuration (allow_origins='*' with allow_credentials=True) combined with a refresh token cookie configured as SameSite=None allows a malicious webpage to perform cross-origin requests that include credentials and successfully call the refresh endpoint. An attacker-controlled origin can therefore obtain fresh access_token / refresh_token pairs for a victim session. Obtained tokens permit access to authenticated endpoints — including built-in code-execution functionality — allowing the attacker to execute arbitrary code and achieve full system compromise.
psychologyCrowdSec Analysis
CVE-2025-34291 is a critical chained vulnerability in Langflow versions up to and including 1.6.9 that allows attackers to take over accounts and execute arbitrary code remotely. By exploiting an insecure CORS configuration and improperly set authentication cookies, a malicious website can steal session tokens and gain access to authenticated endpoints, including those with code execution capabilities. This flaw enables full system compromise and poses a severe risk to affected deployments.
CrowdSec has been tracking this vulnerability and its exploits since 14th of January 2026.
CrowdSec has not observed any significant exploitation activity targeting CVE-2025-34291 across its network. As a result, no community-driven trend analysis is available for this vulnerability at this time.
Attackers exploit CORS misconfigurations by sending cross-origin requests to endpoints like /api/v1/refresh, looking for responses with Access-Control-Allow-Origin set to arbitrary origins and Access-Control-Allow-Credentials: true, which can enable credential theft and further attacks.
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| Event | Date |
|---|---|
| CVE Published | 2025-12-05 |
| Rule Released | 2026-01-14 |
| CrowdSec First Seen | 2026-01-23 |
| CISA KEV | 2026-05-21 |
| CISA Remediation Deadline | 2026-06-04 |
Related Weaknesses
Remediation & Protection
External References
- https://www.obsidiansecurity.com/blog/cve-2025-34291-critical-account-takeover-and-rce-vulnerability-in-the-langflow-ai-agent-workflow-platform
- https://www.vulncheck.com/advisories/langflow-cors-misconfiguration-to-token-hijack-and-rce
- https://github.com/langflow-ai/langflow
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-34291.yaml