Langflow · Langflow
CVE-2025-34291
Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE
What it is
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.
CISA: Langflow contains an origin validation error vulnerability in which an overly permissive CORS configuration 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. This could allow the attacker to execute arbitrary code and achieve full system compromise via obtained tokens that permit access to authenticated endpoints.
What to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Deadline for US federal agencies: June 4, 2026
More exploited flaws from Langflow
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Jul 21, 2026 | Inclusion of Functionality from Untrusted Control Sphere | Langflow | Critical 9.8 | 63% |
| Jul 7, 2026 | Authorization Bypass Through User-Controlled Key | Langflow | High 8.4 | 0.9% |
| Mar 25, 2026 | Code Injection | Langflow | Critical 9.3 | 96% |
| May 5, 2025 | Missing Authentication | Langflow | Critical 9.8 | >99.9% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.