Is CVE-2026-40036 actively exploited?

No active exploitation of CVE-2026-40036 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-40036 be exploited remotely?

Yes. CVE-2026-40036 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-40036?

CVE-2026-40036 has a CVSS score of 7.5 (HIGH).

HOME VULNERABILITIESCVE-2026-40036

HIGH

CVE-2026-40036

CWE-409Published: April 8, 2026· Updated: Apr 13, 2026

7.5

CVSS v3.1

EPSS:0.10%probability of exploitation in 30 daysPercentile:27.7th

Official 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.

NVD Source

Technical Analysis

CVE-2026-40036 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.