CVSS 4.0
8.3 highCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:NCVE-2026-56817
High (8.3) in netty netty. EPSS 0.7% chance of exploitation in the next 30 days. Fixed in io.netty:netty-codec-xml 4.1.136.Final, 4.2.16.Final.
Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and 4.1.0.Final through 4.1.135.Final, any caller that can deliver bytes to a Netty channel pipeline containing `XmlDecoder` can send XML with a `DOCTYPE` declaration to an `AsyncXMLInputFactory` instantiated with no security configuration, leaving DTD and entity handling active depending on Aalto XML async parser behavior and creating conditional XML external entity risk. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Severity
CVSS 3.1
9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- EPSS
- 0.7% chance of exploitation in the next 30 days; higher than 52% of CVEs (scores of 2026-10-31)
- CWE
- CWE-611
- Published
- Modified
- Record from
- the NVD, synced
Affected
- netty:netty
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-4qhr-g3c6-fcfx | Maven | io.netty:netty-codec-xml | >=4.2.0.Final <4.2.16.Final | 4.2.16.Final |
| GHSA-4qhr-g3c6-fcfx | Maven | io.netty:netty-codec-xml | >=4.1.0.Final <4.1.136.Final | 4.1.136.Final |
References
- https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b
- https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6
- https://github.com/netty/netty/releases/tag/netty-4.1.136.Final
- https://github.com/netty/netty/releases/tag/netty-4.2.16.Final
- https://github.com/netty/netty/security/advisories/GHSA-4qhr-g3c6-fcfx