CVE-2026-40036

High

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.

SeverityHigh

CVSS7.5

Exploit probability—

ProductRyandfir Unfurl

PublishedApr 8, 2026

First seenApr 8, 2026

Weakness typeCWE-770Allocation of resources without limits CWE-409CWE-409

How to fix

Update

ryandfir unfurl2026.04 or later
dfir-unfurl20260405 or later

Patches

github.com/obsidianforensics/unfurl/releases/tag/v2026.04

Vendor advisories

github.com/obsidianforensics/unfurl/security/advisories/GHSA-h5qv-qjv4-pc5m

Affected products

Product	Affected versions	Fixed in
ryandfir unfurl	v < 2026.04	2026.04
dfir-unfurlPyPI	v < 20260405	20260405

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