Denial of Service Vulnerability in Netty HTTP/2 Framework
CVE-2026-33871

8.7HIGH

Key Information:

Vendor

Netty

Status
Netty
Vendor
CVE Published:
27 March 2026

What is CVE-2026-33871?

The Netty HTTP/2 Framework is susceptible to a denial of service attack due to the handling of CONTINUATION frames. In vulnerable versions prior to 4.1.132.Final and 4.2.10.Final, a remote attacker can exploit the absence of limits on CONTINUATION frames to trigger excessive CPU usage. This is accomplished by sending a flood of zero-byte CONTINUATION frames, which bypasses existing size-based protections, ultimately leading to server unresponsiveness with minimal network load. Users are urged to upgrade to fixed versions to mitigate this issue.

Affected Version(s)

netty < 4.1.132.Final < 4.1.132.Final

netty >= 4.2.0.Alpha1, < 4.2.10.Final < 4.2.0.Alpha1, 4.2.10.Final

References

https://github.com/netty/netty/security/advisories/GHSA-w...
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CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.