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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Langflow | Langflow | ≤ 1.6.9 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 2 repositories
-
ridhinva/langflow-cors-scanner ★ 0 · May 22, 2026
Scanner: CVE-2025-34291 Langflow Origin Validation Error / CORS Misconfiguration — Python checker (CISA KEV)
-
amnnrth/CVE-2025-34291_cors_security_scanner ★ 0 · May 18, 2026
A lightweight Python-based security assessment tool for detecting dangerous Cross-Origin Resource Sharing (CORS) misconfigurations - CVE-2025-34291.
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Automated scanner template
A ready-made Nuclei template detects this vulnerability automatically. Vulnerabilities with public scanner templates are typically probed across the internet soon after the template appears — exposed systems should be patched first.
- Langflow AI <= 1.6.9 - CORS Misconfiguration http/cves/2025/CVE-2025-34291.yaml
Source: projectdiscovery/nuclei-templates (MIT) — updated daily. Only links are listed.
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | langflow | < 1.7.0 | 1.7.0 | GHSA-577h-p2hh-v4mv |
References
- https://www.obsidiansecurity.com/blog/cve-2025-34291-critical-account-takeover-and-rce-vulnerability-in-the-langflow-ai-agent-workflow-platform technical-description exploit
- https://github.com/langflow-ai/langflow product
- https://www.vulncheck.com/advisories/langflow-cors-misconfiguration-to-token-hijack-and-rce third-party-advisory