CVE-2026-44891
Netty: Denial of Service via Unbounded Headers in StompSubframeDecoder
Description
Netty is a network application framework for development of protocol servers and clients. Prior to 4.1.136.Final and 4.2.16.Final, io.netty.handler.codec.stomp.StompSubframeDecoder fails to limit the total number of headers or their cumulative size per frame, and the maxLineLength parameter only restricts individual header lines. An attacker can send a large number of short headers that are accumulated in memory inside DefaultStompHeadersSubframe until the JVM throws an OutOfMemoryError, causing denial of service for servers exposing a STOMP endpoint based on StompSubframeDecoder. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
INFO
Published Date :
July 17, 2026, 9:17 p.m.
Last Modified :
July 23, 2026, 1:35 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Netty to 4.1.136.Final or later.
- Update Netty to 4.2.16.Final or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-44891.
| URL | Resource |
|---|---|
| https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b | Patch |
| https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6 | Patch |
| https://github.com/netty/netty/pull/17063 | Issue Tracking Patch |
| https://github.com/netty/netty/pull/17065 | Issue Tracking 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-vhch-2wf3-m8rp | Exploit Vendor Advisory |
| https://github.com/netty/netty/security/advisories/GHSA-vhch-2wf3-m8rp | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-44891 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-44891
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-44891 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-44891 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Reanalysis by [email protected]
Jul. 23, 2026
Action Type Old Value New Value Changed CPE Configuration OR *cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* versions up to (excluding) 4.1.136 *cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* versions from (including) 4.2.0 up to (including) 4.2.16 OR *cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* versions up to (excluding) 4.1.136 *cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* versions from (including) 4.2.0 up to (excluding) 4.2.16 -
Initial Analysis by [email protected]
Jul. 22, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* versions up to (excluding) 4.1.136 *cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* versions from (including) 4.2.0 up to (including) 4.2.16 Added Reference Type GitHub, Inc.: https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b Types: Patch Added Reference Type GitHub, Inc.: https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/netty/netty/pull/17063 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/netty/netty/pull/17065 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/netty/netty/releases/tag/netty-4.1.136.Final Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/netty/netty/releases/tag/netty-4.2.16.Final Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/netty/netty/security/advisories/GHSA-vhch-2wf3-m8rp Types: Exploit, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/netty/netty/security/advisories/GHSA-vhch-2wf3-m8rp Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 20, 2026
Action Type Old Value New Value Added Reference https://github.com/netty/netty/security/advisories/GHSA-vhch-2wf3-m8rp Added SSVC {'id': 'CVE-2026-44891', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-20T13:59:43.664113Z'} -
New CVE Received by [email protected]
Jul. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'netty', 'product': 'netty', 'versions': [{'status': 'affected', 'version': '< 4.1.136.Final'}, {'status': 'affected', 'version': '>= 4.2.0.Final, < 4.2.16.Final'}]}] Added Description Netty is a network application framework for development of protocol servers and clients. Prior to 4.1.136.Final and 4.2.16.Final, io.netty.handler.codec.stomp.StompSubframeDecoder fails to limit the total number of headers or their cumulative size per frame, and the maxLineLength parameter only restricts individual header lines. An attacker can send a large number of short headers that are accumulated in memory inside DefaultStompHeadersSubframe until the JVM throws an OutOfMemoryError, causing denial of service for servers exposing a STOMP endpoint based on StompSubframeDecoder. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-400 Added CWE CWE-770 Added Reference https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b Added Reference https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6 Added Reference https://github.com/netty/netty/pull/17063 Added Reference https://github.com/netty/netty/pull/17065 Added Reference https://github.com/netty/netty/releases/tag/netty-4.1.136.Final Added Reference https://github.com/netty/netty/releases/tag/netty-4.2.16.Final Added Reference https://github.com/netty/netty/security/advisories/GHSA-vhch-2wf3-m8rp