CVE-2025-34291 CRITICAL

CVE-2025-34291: Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE

Vendor Langflow
Product Langflow
Weakness CWE-346 · Origin validation
KEV Status Known Exploited
Published December 5, 2025
Last update May 22, 2026

CVSS base score

9.4/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

What the vulnerability does

01Description

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 mandated remediation

02CISA Required Action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Key dates

03Disclosure timeline

December 5, 2025 CVE published
May 22, 2026 Record updated

Related vulnerabilities

05Related CVE