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Vulnerability record · CVE-2026-73507 · published 13 August 2026

CVE-2026-73507: Netty uncontrolled resource consumption vulnerability

Netty · Netty

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.136.Final and 4.2.16.Final, io.netty.handler.codec.xml.XmlFrameDecoder.decode() failed to preserve closing-tag parser state across invocations, so an unauthenticated remote attacker could trickle-feed repeated </ sequences that repeatedly rescanned the accumulated buffer and exhausted an EventLoop thread's CPU, causing denial of service with a maxFrameLength of 1 MB. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

7.5 CVSS 3.1 High EPSS 0.79% · top 45.4% CWE-400 · Uncontrolled resource consumption
7.5CVSS 3.1 base score
0.79%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
5References
23 Sep 2026Last modified by NVD

Description

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.136.Final and 4.2.16.Final, io.netty.handler.codec.xml.XmlFrameDecoder.decode() failed to preserve closing-tag parser state across invocations, so an unauthenticated remote attacker could trickle-feed repeated </ sequences that repeatedly rescanned the accumulated buffer and exhausted an EventLoop thread's CPU, causing denial of service with a maxFrameLength of 1 MB. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

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.

References

LinkTags
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-v74w-7mr3-4qg3 Vendor 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-2026-73507), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.