CVE-2026-48779
HighCVSS 7.5Exploitation Probability (EPSS)
Elevated risk55th percentile - higher than 55% of all known CVEs
Summary
The 'ws' WebSocket library for Node.js is vulnerable to a memory exhaustion DoS attack. An attacker can send a high volume of very small data fragments, forcing the server to allocate wrapper structures that consume far more memory than the default message-size limit, leading to process termination due to OOM.
Risk Assessment
The risk is the ability to remotely crash a Node.js application using the 'ws' library with modest network traffic, potentially causing service disruption and financial or operational losses.
Recommendation
Immediately update the 'ws' library to version 5.2.5, 6.2.4, 7.5.11, or 8.21.0 depending on your major version. If an update is not possible, consider limiting WebSocket connections or applying memory limits at the system level.
Other vulnerabilities in ws
Original NVD description (English source)
ws is an open source WebSocket client and server for Node.js. All versions from 1.1.0 up to (but not including) 5.2.5, from 6.0.0 up to 6.2.4, from 7.0.0 up to 7.5.11, and from 8.0.0 up to 8.21.0 are affected by a memory exhaustion DoS vulnerability. A peer can send a high volume of exceptionally small fragments and data chunks, with modest network traffic, to force the remote peer into allocating and holding structural wrappers that consume far more memory than the default documented message-size limit, leading to process termination due to OOM. This issue has been fixed in versions 5.2.5, 6.2.4, 7.5.11, and 8.21.0.