CVE-2026-40036

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 v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/obsidianforensics/unfurl/releases/tag/v2026.04	Release Notes
https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-h5qv-qjv4-pc5m	Exploit Vendor Advisory
https://www.vulncheck.com/advisories/dfir-unfurl-denial-of-service-via-unbounded-zlib-decompression	Third Party Advisory

Configurations

Configuration 1 (hide)

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

History

17 Apr 2026, 15:56

Type	Values Removed	Values Added
CPE		cpe:2.3:a:ryandfir:unfurl::::::::
First Time		Ryandfir unfurl Ryandfir
References	~~() https://github.com/obsidianforensics/unfurl/releases/tag/v2026.04 -~~	() https://github.com/obsidianforensics/unfurl/releases/tag/v2026.04 - Release Notes
References	~~() https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-h5qv-qjv4-pc5m -~~	() https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-h5qv-qjv4-pc5m - Exploit, Vendor Advisory
References	~~() https://www.vulncheck.com/advisories/dfir-unfurl-denial-of-service-via-unbounded-zlib-decompression -~~	() https://www.vulncheck.com/advisories/dfir-unfurl-denial-of-service-via-unbounded-zlib-decompression - Third Party Advisory

08 Apr 2026, 22:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-08 22:16

Updated : 2026-04-17 15:56

NVD link : CVE-2026-40036

Mitre link : CVE-2026-40036

CVE.ORG link : CVE-2026-40036

JSON object : View

Products Affected

ryandfir

unfurl

CWE

CWE-409

Improper Handling of Highly Compressed Data (Data Amplification)

CWE-770

Allocation of Resources Without Limits or Throttling

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