Vulnerability · Published Jul 17, 2026 · Assigned by GitHub_M

CVE-2026-44891Netty: Denial of Service via Unbounded Headers in StompSubframeDecoder

High 7.5

In plain English

A high-severity uncontrolled resource consumption in netty from netty. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.7%top 45.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	netty	no fix listed	DEBIAN-CVE-2026-44891
Debian:13	netty	no fix listed	DEBIAN-CVE-2026-44891
Debian:14	netty	no fix listed	DEBIAN-CVE-2026-44891
Maven	io.netty:netty-codec-stomp	4.2.16.Final	GHSA-vhch-2wf3-m8rp
Maven	io.netty:netty-codec-stomp	4.1.136.Final	GHSA-vhch-2wf3-m8rp
Ubuntu:26.10	netty	no fix listed	UBUNTU-CVE-2026-44891

Affected products (as reported)

Vendor	Product	Versions
netty	netty	< 4.1.136.Final>= 4.2.0.Final, < 4.2.16.Final

Weakness: CWE-400, CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

https://github.com/netty/netty/security/advisories/GHSA-vhch-2wf3-m8rp x_refsource_CONFIRM
https://github.com/netty/netty/pull/17063 x_refsource_MISC
https://github.com/netty/netty/pull/17065 x_refsource_MISC
https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b x_refsource_MISC
https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6 x_refsource_MISC
https://github.com/netty/netty/releases/tag/netty-4.1.136.Final x_refsource_MISC
https://github.com/netty/netty/releases/tag/netty-4.2.16.Final x_refsource_MISC