Langflow Origin Validation Error
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.
CISA deadline 2026-06-04 · passed 3 months ago · applies to US federal civilian agencies; used elsewhere as a reference SLA
What happened
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.
Who is affected
Langflow Langflow. Affected version ranges are listed in the vendor advisory and the NVD entry linked under Sources.
Weakness class: CWE-346.
Timeline
- Added to CISA KEVExploitation in the wild confirmed by CISA
- CISA remediation deadlinepassed 3 months ago
Sources
- NVD entry for CVE-2025-34291 nvd.nist.gov/vuln/detail/CVE-2025-34291
- CISA Known Exploited Vulnerabilities catalog www.cisa.gov/known-exploited-vulnerabilities-catalog
- github.com github.com/langflow-ai/langflow
- github.com github.com/langflow-ai/langflow/releases/tag/v1.9.3
- github.com github.com/langflow-ai/langflow/issues/11465#event-25774545848
- nvd.nist.gov nvd.nist.gov/vuln/detail/CVE-2025-34291