CVE-2026-83599 (CVSS 7.5)

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.

Is your site exposed to CVE-2026-83599?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0074

Probability of exploitation

0.53%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-409 CWE-409

References

Other References

https://github.com/netdata/netdata/commit/e3811f7ee6e9fdfc4cbcb9929cab3f5d71d722d7 https://github.com/netdata/netdata/pull/22828 https://github.com/netdata/netdata/releases/tag/v2.11.0 https://github.com/netdata/netdata/security/advisories/GHSA-c8p4-cg3j-f4h2

Frequently Asked Questions

What is CVE-2026-83599? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-83599? +

CVE-2026-83599 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0074, placing it in the 1th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-83599? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-44981

CrowdSec offers crowdsourced protection against malicious IPs. From 1.7.0 until 1.7.8, the LAPI router used gin-contrib/gzip with DefaultDecompressHandle globally in …

CVE-2026-58107

CodeChecker's massStoreRun processing path performs one-shot decompression of attacker-controlled, Base64-encoded zlib data without enforcing a maximum decompressed size. An authenticated …

CVE-2026-48594

Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in elixir-tesla tesla allows a denial of service via decompression bomb …

CVE-2026-53430

Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in elixir-grpc grpc (GRPC.Compressor.Gzip, GRPC.Message modules) allows a denial of service …

CVE-2026-67232

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0, The cowboy WebSocket options …

CVE-2026-54556

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, an unauthenticated HTTP/2 peer can cause an …

CVE-2026-83599