Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-40035

CVE-2026-40035CRITICAL

obsidianforensics unfurl — Unfurl - Werkzeug Debugger Exposure via String Config Parsing

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   N   L   N   N   N   H   H   N    9.3   .0072   53.1     —

AFFECTED
  Product  Versions     Fixed
  unfurl   unspecified  —

TIMELINE
  Apr 8   Reserved by VulnCheck
  Apr 8   Published (CNA: VulnCheck)
  Oct 8   EXPLOIT PUBLISHED — CVE-2026-40035 (obsidianforensics unfurl). Public exploit reference added.

CWE-489 · CNA: VulnCheck · CVSS v4.0 · 2 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
April 8, 2026	Reserved	Reserved by VulnCheck
April 8, 2026	Published	Published (CNA: VulnCheck)
October 8, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-40035 (obsidianforensics unfurl). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
obsidianforensics	unfurl	—	—	—

Weaknesses

CWE-489

References (2)

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]

Authoritative record: CVE-2026-40035 at cve.org

Vendors: obsidianforensics

Weaknesses: CWE-489

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-40035 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.