CVE-2026-40035

CRITICAL EPSS 42.2%
Published Apr 8, 20262mo ago · Modified Jun 17, 20262w ago
9.3 CVSS 4.0
Critical
Find Similar
Published Apr 8, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
9.3
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
42.2% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 1

CWE-489

Affected Products 1

VendorProductVersionRange
ryandfirunfurl* ≤2025.08

References 2

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

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.