CVE-2026-40035

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.

CVSS v3 9.1 CRITICAL

9.1^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-vg9h-jx4v-cwx2	Exploit Vendor Advisory
https://www.vulncheck.com/advisories/dfir-unfurl-werkzeug-debugger-exposure-via-string-config-parsing	Third Party Advisory
https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-vg9h-jx4v-cwx2	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:ryandfir:unfurl:*:*:*:*:*:*:*:*

History

17 Apr 2026, 16:03

Type	Values Removed	Values Added
First Time		Ryandfir unfurl Ryandfir
CPE		cpe:2.3:a:ryandfir:unfurl::::::::
References	~~() https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-vg9h-jx4v-cwx2 -~~	() https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-vg9h-jx4v-cwx2 - Exploit, Vendor Advisory
References	~~() https://www.vulncheck.com/advisories/dfir-unfurl-werkzeug-debugger-exposure-via-string-config-parsing -~~	() https://www.vulncheck.com/advisories/dfir-unfurl-werkzeug-debugger-exposure-via-string-config-parsing - Third Party Advisory

09 Apr 2026, 14:16

Type	Values Removed	Values Added
References	~~() https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-vg9h-jx4v-cwx2 -~~	() https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-vg9h-jx4v-cwx2 -

08 Apr 2026, 22:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-08 22:16

Updated : 2026-04-17 16:03

NVD link : CVE-2026-40035

Mitre link : CVE-2026-40035

CVE.ORG link : CVE-2026-40035

JSON object : View

Products Affected

ryandfir

unfurl

CWE

CWE-489

Active Debug Code

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