Netty XML: Injection / Risky Sink — unconfigured XML factory with active DTD and entity handling
Any caller that can deliver bytes to a Netty channel pipeline containing XmlDecoder can send XML with a DOCTYPE declaration to a parser instantiated with no security configuration — but whether external entities are actually resolved depends on Aalto XML's async parser behavior, making this a confirmed misconfiguration with conditional exploitability.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | io.netty:netty-codec-xml | >= 4.2.0.Final, < 4.2.16.Final, >= 4.1.0.Final, < 4.1.136.Final | 4.2.16.Final, 4.1.136.Final |
References
- https://github.com/netty/netty/security/advisories/GHSA-4qhr-g3c6-fcfx
- https://nvd.nist.gov/vuln/detail/CVE-2026-56817
- 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
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N- Weakness (CWE)
CWE-611- Platform
- Java / Kotlin (Maven)
- Package
io.netty:netty-codec-xml- Disclosed
- 22.07.2026
- Updated
- 11.10.2026 13:20
Sources and licenses
OSV / GitHub Advisory Database - GHSA-4qhr-g3c6-fcfx - CC BY 4.0
Vulnerability history: io.netty:netty-codec-xml
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 07.2026 07.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 2
Disclosures per year
- 2026: 2
-
Netty XML: Injection / Risky Sink — unconfigured XML factory with active DTD and entity handling this entry
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