CVE intelligence and bounded remediation

CVE-2025-34291 — Langflow Origin Validation Error Vulnerability

Critical CVSS 9.4 CISA KEV

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.

Severity
Critical
CVSS
9.4 (4.0)
Published
2025-12-05
CISA KEV
Known exploited
Ecosystem
software/application
Weaknesses
CWE-346

Affected products

  • langflow / langflow

Matched remediation archetype

Command, code, expression, and template injection

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Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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