Netty: Denial of Service in XmlFrameDecoder via CPU Exhaustion
Summary
An attacker can cause Denial of Service by sending a specially crafted malicious XML payload (e.g., repeated </ characters) to a Netty server utilizing XmlFrameDecoder, causing the server's EventLoop thread to exhaust CPU resources and become unresponsive.
Details
io.netty.handler.codec.xml.XmlFrameDecoder suffers from a vulnerability resulting in CPU exhaustion. When < followed by / is encountered, the decoder scans the remaining buffer for a closing >.
Because the parser state is not saved between decode() invocations, an attacker can trickle-feed a payload of </ characters. This forces the decoder to repeatedly rescan the entire accumulated buffer. A 1MB maxFrameLength is enough to completely hang a server's thread while it loops endlessly.
Impact
Denial of Service via CPU Exhaustion. Any application utilizing Netty's XmlFrameDecoder is impacted. An unauthenticated remote attacker can exploit this flaw by sending a modest amount of malformed XML data to an exposed port.
Software afectado
Haz clic en una tecnología para ver todas sus vulnerabilidades.
| Plataforma | Paquete | Versiones vulnerables | Corregida en |
|---|---|---|---|
| Java / Kotlin (Maven) | io.netty:netty-codec-xml | >= 4.2.0.Final, < 4.2.16.Final, < 4.1.136.Final | 4.2.16.Final, 4.1.136.Final |
Referencias
- https://github.com/netty/netty/security/advisories/GHSA-v74w-7mr3-4qg3
- https://github.com/netty/netty/pull/17063
- https://github.com/netty/netty/pull/17065
- https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b
- https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6
- https://github.com/netty/netty
- https://github.com/netty/netty/releases/tag/netty-4.1.136.Final
- https://github.com/netty/netty/releases/tag/netty-4.2.16.Final
- Vector CVSS
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Debilidad (CWE)
CWE-400- Plataforma
- Java / Kotlin (Maven)
- Paquete
io.netty:netty-codec-xml- Publicada
- 24.07.2026
- Actualizado
- 11.10.2026 13:20
Fuentes y licencias
OSV / GitHub Advisory Database - GHSA-v74w-7mr3-4qg3 - CC BY 4.0
Historial de vulnerabilidades: io.netty:netty-codec-xml
Todas las vulnerabilidades publicadas de este paquete (Java / Kotlin (Maven)), de la más reciente a la más antigua. Muestra si es un fallo aislado o un paquete que hay que vigilar.
- Entradas en total
- 2
- Primera → última
- 07.2026 07.2026
- Sin corrección
- 0
- Explotada en ataques
- 0
Distribución por gravedad
- Alta 2
Divulgaciones por año
- 2026: 2
-
Netty: Denial of Service in XmlFrameDecoder via CPU Exhaustion esta entrada
Identifica las vulnerabilidades de tu aplicación
Con la integración de DockRay y el inventario de software activado, DockRay compara las versiones notificadas de los componentes con las vulnerabilidades conocidas y avisa de las coincidencias confirmadas. La cobertura depende de la tecnología compatible y de los avisos disponibles.