CVSS 4.0
8.7 highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NCVE-2026-33871
High (8.7) in netty netty. EPSS 1.1% chance of exploitation in the next 30 days. Fixed in io.netty:netty-codec-http2 4.1.132.Final, 4.2.11.Final.
Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, a remote user can trigger a Denial of Service (DoS) against a Netty HTTP/2 server by sending a flood of `CONTINUATION` frames. The server's lack of a limit on the number of `CONTINUATION` frames, combined with a bypass of existing size-based mitigations using zero-byte frames, allows an user to cause excessive CPU consumption with minimal bandwidth, rendering the server unresponsive. Versions 4.1.132.Final and 4.2.10.Final fix the issue.
Severity
CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- EPSS
- 1.1% chance of exploitation in the next 30 days; higher than 66% of CVEs (scores of 2026-10-31)
- CWE
- CWE-770
- Published
- Modified
- Record from
- the NVD, synced
Affected
- netty:netty
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-w9fj-cfpg-grvv | Maven | io.netty:netty-codec-http2 | <4.1.132.Final | 4.1.132.Final |
| GHSA-w9fj-cfpg-grvv | Maven | io.netty:netty-codec-http2 | >=4.2.0.Alpha1 <4.2.11.Final | 4.2.11.Final |