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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-40036 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  VulnCheck
CVSS-B 8.7 HIGH
Vector:  CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References to Advisories, Solutions, and Tools

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

Weakness Enumeration

CWE-ID CWE Name Source
CWE-409 Improper Handling of Highly Compressed Data (Data Amplification) VulnCheck  
CWE-770 Allocation of Resources Without Limits or Throttling VulnCheck  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

4 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-40036
NVD Published Date:
04/08/2026
NVD Last Modified:
06/17/2026
Source:
VulnCheck