Is CVE-2018-6333 actively exploited?

No active exploitation of CVE-2018-6333 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2018-6333 be exploited remotely?

Yes. CVE-2018-6333 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2018-6333?

CVE-2018-6333 has a CVSS score of 9.8 (CRITICAL).

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CRITICAL

CVE-2018-6333

CWE-79Published: December 31, 2018· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

The hhvm-attach deep link handler in Nuclide did not properly sanitize the provided hostname parameter when rendering. As a result, a malicious URL could be used to render HTML and other content inside of the editor's context, which could potentially be chained to lead to code execution. This issue affected Nuclide prior to v0.290.0.

NVD Source

Technical Analysis

CVE-2018-6333 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 complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.