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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-40035 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  VulnCheck
CVSS-B 9.3 CRITICAL
Vector:  CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-vg9h-jx4v-cwx2 VulnCheck
https://www.vulncheck.com/advisories/dfir-unfurl-werkzeug-debugger-exposure-via-string-config-parsing VulnCheck

Weakness Enumeration

CWE-ID CWE Name Source
CWE-489 Active Debug Code VulnCheck  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-40035
NVD Published Date:
04/08/2026
NVD Last Modified:
04/08/2026
Source:
VulnCheck