CVE-2026-40036

HIGH

7.5

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.

CVE Details

CVSS v3.1 Score7.5

SeverityHIGH

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredNONE

User InteractionNONE

Published4/8/2026

Last Modified4/17/2026

Sourcenvd

Honeypot Sightings0

Affected Products

ryandfir:unfurl

Weaknesses (CWE)

CWE-409CWE-770

References

https://github.com/obsidianforensics/unfurl/releases/tag/v2026.04(disclosure@vulncheck.com)

https://github.com/obsidianforensics/unfurl/security/advisories/GHSA-h5qv-qjv4-pc5m(disclosure@vulncheck.com)

https://www.vulncheck.com/advisories/dfir-unfurl-denial-of-service-via-unbounded-zlib-decompression(disclosure@vulncheck.com)

IOC Correlations

No correlations recorded

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