Langflow Origin Validation Error Vulnerability

Langflow Langflow

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. Added to CISA KEV on 2026-05-21 (federal deadline 2026-06-04).

First seen: 21 May 2026
Last update: 21 May 2026, 12:00 UTC
Identifiers: CVE-2025-34291
Source: CISA KEV
On the menu as: LLM gateways

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Langflow Origin Validation Error Vulnerability
Severity: high, exploited in the wild. Patch status: patched.
Affected: Langflow Langflow
Ids: CVE-2025-34291

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. Added to CISA KEV on 2026-05-21 (federal deadline 2026-06-04).

## Steps
1. This incident involves a provider (ai-gateways). Search config, CI and env templates (.env.example, wrangler.toml, vercel.json, terraform, workflow secrets) for credentials stored there. List each secret by name, where it is used, and how to rotate it. Never print secret values.

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2025-34291") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://github.com/langflow-ai/langflow/issues/11465#event-25774545848 https://github.com/langflow-ai/langflow/releases/tag/v1.9.3 https://nvd.nist.gov/vuln/detail/CVE-2025-34291
https://pwned.coffee/i/langflow-origin-validation-error-vulnerability-cve-2025-34291

Sources

Totalone hot coffee