Security Vulnerability in Netty Framework Affects XML Processing
CVE-2026-56817

8.3HIGH

Key Information:

Vendor

Netty

Status
Netty
Vendor
CVE Published:
21 July 2026

What is CVE-2026-56817?

The Netty framework is exposed to a vulnerability allowing attackers to deliver malicious XML content via the XmlDecoder if the AsyncXMLInputFactory is not configured securely. This enables the processing of Document Type Definitions (DTDs), which could lead to XML external entity injections, potentially allowing unauthorized access to sensitive data or server-side resource exploitation. It is critical for users of the affected versions to update to at least 4.1.136.Final or 4.2.16.Final to mitigate these risks.

Affected Version(s)

netty >= 4.2.0.Final, < 4.2.16.Final < 4.2.0.Final, 4.2.16.Final

netty >= 4.1.0.Final, < 4.1.136.Final < 4.1.0.Final, 4.1.136.Final

References

https://github.com/netty/netty/security/advisories/GHSA-4...
x_refsource_CONFIRM
https://github.com/netty/netty/commit/5b68c61f37aa4a3045c...
x_refsource_MISC
https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0e...
x_refsource_MISC

CVSS V4

Score:
8.3
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.