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Vulnerability · Published Jun 16, 2026 · Assigned by GitHub_M

CVE-2026-48779ws: Memory exhaustion DoS from tiny fragments and data chunks

High 7.5

In plain English

A high-severity uncontrolled resource consumption in ws from websockets. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.4% (higher than 73% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)1.4%top 26.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12node-wsno fix listedDEBIAN-CVE-2026-48779
Debian:13node-wsno fix listedDEBIAN-CVE-2026-48779
Debian:14node-ws8.21.0+~cs14.19.1-1DEBIAN-CVE-2026-48779
Ubuntu:22.04:LTSnode-wsno fix listedUBUNTU-CVE-2026-48779
Ubuntu:24.04:LTSnode-wsno fix listedUBUNTU-CVE-2026-48779
Ubuntu:25.10node-wsno fix listedUBUNTU-CVE-2026-48779
Ubuntu:26.04:LTSnode-wsno fix listedUBUNTU-CVE-2026-48779
Ubuntu:26.10node-wsno fix listedUBUNTU-CVE-2026-48779
npmws8.21.0GHSA-96hv-2xvq-fx4p
npmws7.5.11GHSA-96hv-2xvq-fx4p
npmws6.2.4GHSA-96hv-2xvq-fx4p
npmws5.2.5GHSA-96hv-2xvq-fx4p

Affected products (as reported)

VendorProductVersions
websockets ws >= 1.1.0, < 5.2.5>= 6.0.0, < 6.2.4>= 7.0.0, < 7.5.11>= 8.0.0, < 8.21.0

Weakness: CWE-400, CWE-770, CWE-1050 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References