CVE-2026-44891

Netty: Denial of Service via Unbounded Headers in StompSubframeDecoder

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

netty

CVSS v3.1 GITHUB

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

EPSS

0.73% chance of exploitation in the next 30 days, 53rd percentile

Published

2026-07-17

Updated

2026-07-20

Proof-of-concept exploits (1)

• advisories/GHSA-vhch-2wf3-m8rp

Security advisories

• netty/netty/security/advisories/GHSA-vhch-2wf3-m8rp
• netty/netty/pull/17063

References

• CVE Record
• NVD entry