Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Netty's netty-codec-http package, versions 4.2.0.Alpha1 up to but not including 4.2.13.Final and 4.1 versions before 4.1.133.Final, is affected. When HttpClientCodec is used with HTTP/1.1 pipelining and a HEAD request in the pipeline, a server sending a 1xx informational response can cause a response body to be parsed as the response to a different request, desynchronizing the connection. The source gives few details on the attacker's position or exact impact beyond integrity and availability of HTTP parsing on the connection. Upgrade to 4.2.13.Final or 4.1.133.Final.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 7.3 | High | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0084, the 57th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:16 UTC First seen by agentprime
- 31 Oct 2026, 14:16 UTC Confirmed by OSV