Vulnerability record · CVE-2026-55833 · published 21 July 2026

CVE-2026-55833: Netty uncontrolled resource consumption vulnerability

Netty · Netty

Netty is a network application framework for development of protocol servers and clients. Prior to 4.1.136.Final and 4.2.16.Final, Netty SPDY header decoding continues inflating zlib-compressed header blocks after the raw header parser has exceeded `maxHeaderSize` and marked the frame truncated in `SpdyFrameCodec`, allowing a remote peer to send a small compressed `HEADERS` block that expands into much larger raw header data and causes compression-amplified CPU and allocation churn. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

7.5 CVSS 3.1 High EPSS 0.66% · top 50.2% CWE-400 · Uncontrolled resource consumption

7.5CVSS 3.1 base score

0.66%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

5References, 1 tagged exploit

23 Jul 2026Last modified by NVD

Description

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Netty Netty

References

Link	Tags
https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b	Patch
https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6	Patch
https://github.com/netty/netty/releases/tag/netty-4.1.136.Final	Release Notes
https://github.com/netty/netty/releases/tag/netty-4.2.16.Final	Release Notes
https://github.com/netty/netty/security/advisories/GHSA-mvh2-crg5-v77c	ExploitVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-55833), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.