CVE-2026-1526
undici: undici: Denial of Service via unbounded memory consumption during WebSocket permessage-deflate decompression
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · March 13, 2026
Updated · October 27, 2026
Description
A flaw was found in undici. A remote attacker can exploit this vulnerability by sending a specially crafted compressed frame, known as a "decompression bomb," during permessage-deflate decompression. The undici WebSocket client does not properly limit the size of decompressed data, leading to unbounded memory consumption. This can cause the Node.js process to exhaust available memory, resulting in a denial of service (DoS) where the process crashes or becomes unresponsive.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-770 · Allocation of Resources Without Limits or Throttling