CVE-2025-34291

Langflow

Published 5 Dec 2025 · updated 14 Jul 2026 · Analyzed

9.4 Critical · CVSS 4.0, vulncheck.com

Exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on 21 May 2026, with a remediation deadline of 4 Jun 2026 for US federal agencies.

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.

Description

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.

References