Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Netty's io.netty:netty-codec-http is vulnerable to request smuggling in versions from 4.2.0.Alpha1 up to 4.2.13.Final and in versions before 4.1.133.Final. When an HTTP/1.0 request carries both Transfer-Encoding: chunked and Content-Length, Netty keeps the Content-Length header while decoding the body as chunked, so a downstream proxy that trusts Content-Length can misread message boundaries. An attacker who can send such requests may be able to smuggle a second request, which could enable cache poisoning or bypass of front-end controls. 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 |
|---|---|---|---|---|
| 5.8 | Medium | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0063, the 50th 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