CVE-2026-83599
Received Received - Intake

Memory Exhaustion in Netdata via WebSocket Compression

Publication date: 2026-09-22

Last updated on: 2026-09-22

Assigner: GitHub, Inc.

Description
Netdata is an open source observability tool. Prior to 2.11.0, Netdata's unauthenticated WebSocket server negotiates permessage-deflate before authentication, and src/web/websocket/websocket-compression.c allows websocket_client_decompress_message() to grow decompressed output toward WS_MAX_DECOMPRESSED_SIZE without enforcing a compressed-to-decompressed ratio. Small highly compressed frames can therefore cause large server-side allocations, and repeated concurrent connections can exhaust memory and terminate monitoring. This vulnerability is fixed in 2.11.0.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-09-22
Last Modified
2026-09-22
Generated
2026-09-22
AI Q&A
2026-09-22
EPSS Evaluated
N/A
NVD
CVE-2026-83599
EUVD
EUVD-2026-84561

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
netdata netdata to 2.11.0 (exc)
netdata netdata 2.11.0

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-409 The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability is a decompression bomb attack in Netdata's WebSocket server. It allows unauthenticated attackers to send small compressed messages that decompress to very large sizes, causing the server to allocate excessive memory and crash. The issue occurs because the server does not validate the ratio between compressed and decompressed data sizes before processing.

Detection Guidance

Monitor for unusual memory consumption on the Netdata server, particularly when WebSocket connections are active. Check for processes exceeding normal memory usage or system slowdowns during WebSocket traffic. Use tools like 'top', 'htop', or 'ps' to observe memory usage by the Netdata process.

Impact Analysis

An attacker could exploit this to crash your Netdata server by sending specially crafted compressed WebSocket messages. This would cause memory exhaustion, leading to denial of service and disrupting monitoring and observability functions. The attack requires no authentication and can be executed remotely.

Mitigation Strategies

Upgrade Netdata to version 2.11.0 or later to apply the decompression-bomb guard fix. If upgrading is not immediately possible, disable WebSocket compression or restrict unauthenticated WebSocket connections until the update is applied.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-83599. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart