CVE-2026-1526

CVE Details

Release Date:	2026-03-12
Impact:	Important	What is this?

Description

The undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression. When a WebSocket connection negotiates the permessage-deflate extension, the client decompresses incoming compressed frames without enforcing any limit on the decompressed data size. A malicious WebSocket server can send a small compressed frame (a "decompression bomb") that expands to an extremely large size in memory, causing the Node.js process to exhaust available memory and crash or become unresponsive. The vulnerability exists in the PerMessageDeflate.decompress() method, which accumulates all decompressed chunks in memory and concatenates them into a single Buffer without checking whether the total size exceeds a safe threshold.

See more information about CVE-2026-1526 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	7.5
Vector String:	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Version:	3.1
Attack Vector:	Network
Attack Complexity:	Low
Privileges Required:	None
User Interaction:	None
Scope:	Unchanged
Confidentiality Impact:	None
Integrity Impact:	None
Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 10 (nodejs22)	ELSA-2026-7080	2026-04-08
Oracle Linux version 8 (nodejs)	ELSA-2026-7123	2026-04-09
Oracle Linux version 8 (nodejs-nodemon)	ELSA-2026-7123	2026-04-09
Oracle Linux version 8 (nodejs-packaging)	ELSA-2026-7123	2026-04-09
Oracle Linux version 9 (nodejs)	ELSA-2026-7302	2026-04-10
Oracle Linux version 9 (nodejs)	ELSA-2026-7350	2026-04-10
Oracle Linux version 9 (nodejs-nodemon)	ELSA-2026-7302	2026-04-10
Oracle Linux version 9 (nodejs-nodemon)	ELSA-2026-7350	2026-04-10
Oracle Linux version 9 (nodejs-packaging)	ELSA-2026-7302	2026-04-10
Oracle Linux version 9 (nodejs-packaging)	ELSA-2026-7350	2026-04-10