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CVE-2025-34291: Langflow Origin Validation Error Vulnerability

Langflow Langflow · in CISA KEV since 2026-05-21

2026-05-21added to KEV

2026-06-04federal remediation due date

83.63%EPSS exploit probability (30 days) 99.7th percentile

9.4 CRITICALCVSS 4.0

Unknownknown ransomware use

167days from NVD publication to KEV

What it is

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.

Required action (CISA)

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

CWE	CWE-346
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X`
NVD published	2025-12-05 (Analyzed)

Original records: NVD · CISA KEV · JSON: /api/cve/CVE-2025-34291.json · all KEV CVEs

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