NVD CRITICAL: CVE-2026-40035 — Unfurl through 2025.08 contains an improper input validation vulnerability in co...

Wednesday, April 8, 2026 at 10:16 PM UTC·Source: NIST NVD

Updated: Wednesday, April 8, 2026 at 10:17 PM UTC

Executive Summary

Unfurl through 2025.08 contains an improper input validation vulnerability in config parsing that enables Flask debug mode by default. The debug configuration value is read as a string and passed directly to app.run(), causing any non-empty string to evaluate truthy, allowing attackers to access the Werkzeug debugger and disclose sensitive information or achieve remote code execution.

Analysis

Indicators of Compromise (1)

CVE (1)

CVE-2026-40035

NVD MITRE CVE

Source Attribution

Originally published by NIST NVD on Apr 8, 2026. Verified by: NIST.

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