Vulnerability Description
Unfurl before 2026.04 contains an unbounded zlib decompression vulnerability in parse_compressed.py that allows remote attackers to cause denial of service. Attackers can submit highly compressed payloads via URL parameters to the /json/visjs endpoint that expand to gigabytes, exhausting server memory and crashing the service.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ryandfir | Unfurl | < 2026.04 |
Related Weaknesses (CWE)
References
- https://github.com/obsidianforensics/unfurl/releases/tag/v2026.04Release Notes
- https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-h5qv-qjv4-pExploitVendor Advisory
- https://www.vulncheck.com/advisories/dfir-unfurl-denial-of-service-via-unboundedThird Party Advisory
FAQ
What is CVE-2026-40036?
CVE-2026-40036 is a vulnerability with a CVSS score of 7.5 (HIGH). Unfurl before 2026.04 contains an unbounded zlib decompression vulnerability in parse_compressed.py that allows remote attackers to cause denial of service. Attackers can submit highly compressed payl...
How severe is CVE-2026-40036?
CVE-2026-40036 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-40036?
Check the references section above for vendor advisories and patch information. Affected products include: Ryandfir Unfurl.