Langflow - RCE (CVE-2025-34291)
20Exploiting IPs reported
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.
CrowdSec 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 network observations suggest that most exploitation of CVE-2025-34291 involves focused reconnaissance to identify viable targets. Attackers typically tailor their campaigns based on system exposure and configuration. It is unlikely that a given attack is accidental. Additionally, according to week-over-week analysis by CrowdSec, exploitation of CVE-2025-34291 is surging. Attack volumes are spiking well above historical norms, indicating widespread and escalating interest from threat actors. CVE-2025-34291 is currently experiencing high visibility and active exploitation across the internet.
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.
Exploitation
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Common Weakness Enumeration (CWE)
Protection
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Blocklist
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