CVE-2026-40035CWE-489

CVE-2026-40035

Critical · published April 9, 2026

CVSS v3.1
9.1
EPSS
1%
Percentile
53.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.1 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00722 · 53.4th percentile
Weakness
CWE-489 · Active Debug Code
Published
2026-04-09T02:16Z
Affected products (1)
ProductVersionsFixed in
ryandfir/unfurl≤ 2025.08—
References (3)
https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-vg9h-jx4v-cwx2 · [email protected]https://www.vulncheck.com/advisories/dfir-unfurl-werkzeug-debugger-exposure-via-string-config-parsing · [email protected]https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-vg9h-jx4v-cwx2 · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 08 APR 21:35Z
    Unfurl - Werkzeug Debugger Exposure via String Config Parsing
    cvelistv5