CVE-2026-45736: ws — Exploit & Fix

Description

ws is an open source WebSocket client and server for Node.js. Prior to 8.20.1, the websocket.close() implementation is vulnerable to uninitialized memory disclosure when a TypedArray is passed as the reason argument. This vulnerability is fixed in 8.20.1.

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CVSS v3.1 Score

4.4

MEDIUM

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

EPSS — Exploit Prediction

0.0001

Probability of exploitation

0.02%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-908 CWE-908

Affected Products

Vendor	Product	Versions
ws_project	ws	8.0.0 — 8.20.1

References

Advisories & Patches

https://github.com/websockets/ws/commit/c0327ec15a54d701eb6ccefaa8bef328cfc03086 https://github.com/websockets/ws/security/advisories/GHSA-58qx-3vcg-4xpx https://github.com/websockets/ws/security/advisories/GHSA-58qx-3vcg-4xpx

Exploits

https://github.com/websockets/ws/security/advisories/GHSA-58qx-3vcg-4xpx https://github.com/websockets/ws/security/advisories/GHSA-58qx-3vcg-4xpx

Frequently Asked Questions

What is CVE-2026-45736? +

ws is an open source WebSocket client and server for Node.js. Prior to 8.20.1, the websocket.close() implementation is vulnerable to uninitialized memory disclosure when a TypedArray is passed as the reason argument. This vulnerability is fixed in 8.20.1. It has a CVSS v3.1 base score of 4.4 (MEDIUM).

How severe is CVE-2026-45736? +

CVE-2026-45736 has a CVSS v3.1 score of 4.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0001, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-45736? +

CVE-2026-45736 affects products from ws_project, specifically: ws. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-45736? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2026-45736