CVE-2025-34291: Active Exploitation of LangFlow RCE Confirmed in the Wild
Last week, the CrowdSec Intelligence Network added another batch of detection rules for CVEs released in Q4 of 2025. Among these is CVE-2025-34291, a remote code execution vulnerability in LangFlow, one of the most popular AI agent frameworks. Using data provided by the CrowdSec Network, we are now the first to confirm that this vulnerability is being actively exploited in the wild. Security teams that have not patched the vulnerability yet must now act quickly to protect their LangFlow instances.
Key findings
Active exploitation of CVE-2025-34291 was observed starting on January 23rd, 2026. The vulnerability has not yet been added to CISA KEV, but we expect this to happen soon.
CVE-2025-34291 originates from an issue in the cross-site request forgery protection of the LangFlow default configuration. As a consequence, the IPs observed by CrowdSec are the IPs of users falling for the ruse of the threat actors using this vulnerability.
Due to how the vulnerability works in practice, CrowdSec cannot fully confirm the scale of the exploitation campaign. However, from the data available, we can conclude that the operation is probably being orchestrated on a professional scale.
How does CVE-2025-34291 work?
CVE-2025-34291 is a nasty chain of configuration issues involving CORS (Cross-Origin Resource Sharing) and SameSite cookie attributes. We provide a short summary for brevity.
