CVE-2026-40035
CRITICALDescription
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.
How to fix
No published remediation has been found for this vulnerability's affected products yet.
Mitigation guidance may be in the linked vendor advisories in the References section below.
TridentStack Control tracks known vulnerabilities across your Windows, macOS, and Linux fleet and shows the fix as soon as one is published. See how it works
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Exploit Intelligence
Moderate risk: more likely to be exploited than 43% of all known CVEs.
References
Related Vulnerabilities
Other CWE-489 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2023-32645 | Critical | 9.8 | 54% | - | - |
| CVE-2017-5259 | High | 8.8 | 39% | - | - |
| CVE-2022-20649 | High | 8.1 | 12% | - | - |
| CVE-2022-38715 | High | 8.8 | 3.7% | - | - |
| CVE-2018-5454 | High | 8.1 | 3.5% | - | - |
| CVE-2021-3972 | Medium | 6.7 | 3.0% | - | Fix |
Common questions
How do I fix CVE-2026-40035?
No published fix for CVE-2026-40035 has been found yet. Check the linked vendor advisories for guidance as it becomes available.
Is CVE-2026-40035 being actively exploited?
Not that we know of. CVE-2026-40035 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.56% is the estimated probability that it will be exploited in the next 30 days. That is higher than 43% of all scored CVEs.
How severe is CVE-2026-40035?
CVE-2026-40035 has a CVSS v3 base score of 9.1, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
Embed a live status badge for CVE-2026-40035
Markdown
[](https://tridentstack.com/cve/CVE-2026-40035)HTML
<a href="https://tridentstack.com/cve/CVE-2026-40035"><img src="https://tridentstack.com/cve/badge/CVE-2026-40035.svg" alt="CVE-2026-40035"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-24.