Denial-of-Service Vulnerability in Netty HTTP/3 Codec from Netty
CVE-2026-100661

8.7HIGH

Key Information:

Vendor

Netty

Status
Netty
Vendor
CVE Published:
26 September 2026

What is CVE-2026-100661?

A vulnerability exists in the Netty HTTP/3 codec associated with the QPACK prefixed-integer decoder, allowing a remote, unauthenticated attacker to exploit unbounded processing of continuation bytes. This may lead to unbounded heap growth and CPU starvation on event loops, causing potential disruptions in service. The issue arises when the decoder is fed a specific sequence of bytes that leads to excessive resource consumption. The problem has been addressed in version 4.2.18.Final.

Affected Version(s)

netty 4.2.0.Final < 4.2.18.Final

netty 4.2.18.Final

References

https://github.com/netty/netty/security/advisories/GHSA-v...
vendor-advisory
https://www.vulncheck.com/advisories/netty-http-3-qpack-p...
third-party-advisory

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

Credit

manus-use
.