CVE-2026-40035
High
High exploit probability or critical severity with a known exploit.
CVSS base
9.1
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS — probability of exploitation (30 days)
0.6%
45.2th percentile
CISA KEV
Not listed
Weakness / dates
CWE-489
Published 2026-04-08 · modified 2026-07-24
Description
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.