All vulnerabilities
CVE-2025-34291

Langflow Origin Validation Error Vulnerability

Langflow LangflowApplications & CMS
Open in ThreatlineRecord JSON
CVSS
9.4Critical
ExploitationExploited in the wildAdded to KEV 21 May 2026CISA KEV
Exploit odds (EPSS)92.8%Chance of exploitation activity in the next 30 days, higher than 99% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Federal deadline4 Jun 2026Remediation due date for US federal agenciesCISA KEV
CISA required actionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. CISA KEV

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Timeline

  1. 5 Dec 2025, 22:27 UTCPublishedCVE List
  2. 21 May 2026Added to CISA KEVCISA KEV

Public exploit code and templates 1

  • Scanner templateLangflow AI <= 1.6.9 - CORS MisconfigurationNuclei

Listed so defenders can prioritize. Threatline links to the source and does not host exploit code.

Description

Langflow contains an origin validation error vulnerability in which an overly permissive CORS configuration 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. This could allow the attacker to execute arbitrary code and achieve full system compromise via obtained tokens that permit access to authenticated endpoints.

Text from CVE List

Affected versions 1

  • Langflowaffected: all versions through 1.6.9CVE List

References 8