CVE-2025-34291

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.

Score

CVSS 4.0 9.4 Critical

Status

Analyzed - disclosure@vulncheck.com

Published

2025-12-05

Last modified

2026-10-15

Known exploited (CISA KEV)

since 2026-05-21, action due 2026-06-04: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Weaknesses

CWE-346

Affected products

• Langflow (Langflow)

References

• https://www.obsidiansecurity.com/blog/cve-2025-34291-critical-account-takeover-and-rce-vulnerability-in-the-langflow-ai…
• https://github.com/langflow-ai/langflow
• https://www.vulncheck.com/advisories/langflow-cors-misconfiguration-to-token-hijack-and-rce
• https://www.crowdsec.net/vulntracking-report/cve-2025-34291
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-34291