Langflow CORS misconfiguration enables Account Takeover and RCE

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.

CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Severity from

GitHub (reviewed advisory)

Weakness

CWE-346

Also known as

CVE-2025-34291, PYSEC-2025-78

• nvd.nist.gov/vuln/detail/CVE-2025-34291
• github.com/langflow-ai/langflow/pull/10139
• github.com/langflow-ai/langflow/pull/10696
• github.com/langflow-ai/langflow/pull/9240
• github.com/langflow-ai/langflow/pull/9441
• github.com/langflow-ai/langflow
• github.com/pypa/advisory-database/tree/main/vulns/langflow/PYSEC-2025-78.yaml
• www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-34291
• www.crowdsec.net/vulntracking-report/cve-2025-34291
• www.obsidiansecurity.com/blog/cve-2025-34291-critical-account-takeover-and-rce-vulnerability-in-the-langflow-ai-agent-workflow-platform
• www.vulncheck.com/advisories/langflow-cors-misconfiguration-to-token-hijack-and-rce