CVE-2025-34291 PUBLISHED

Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE

Assigner: VulnCheck
Reserved: 15.04.2025 Published: 05.12.2025 Updated: 08.12.2025

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.

Metrics

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
CVSS Score: 9.4

Product Status

Vendor Langflow
Product Langflow
Versions Default: unaffected
  • affected from 0 to 1.6.9 (incl.)

Credits

  • Fenix Qiao (aka 13ph03nix) from Obsidian Security finder
  • Shuyang Wang from Obsidian Security finder

References

Problem Types

  • CWE-346 Origin Validation Error CWE

Impacts

  • CAPEC-160 Exploit Script-Based APIs
  • CAPEC-21 Exploitation of Trusted Identifiers