CVE-2026-42581
Publication date 13 May 2026
Last updated 8 June 2026
Ubuntu priority
Description
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpObjectDecoder strips a conflicting Content-Length header when a request carries both Transfer-Encoding: chunked and Content-Length, but only for HTTP/1.1 messages. The guard is absent for HTTP/1.0. An attacker that sends an HTTP/1.0 request with both headers causes Netty to decode the body as chunked while leaving Content-Length intact in the forwarded HttpMessage. Any downstream proxy or handler that trusts Content-Length over Transfer-Encoding will disagree on message boundaries, enabling request smuggling. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| netty | 26.04 LTS resolute |
Fixed 1:4.1.48-16ubuntu0.1~esm2
|
| 25.10 questing |
Vulnerable
|
|
| 24.04 LTS noble |
Fixed 1:4.1.48-9ubuntu0.1+esm3
|
|
| 22.04 LTS jammy |
Fixed 1:4.1.48-4+deb11u2ubuntu0.1+esm3
|
|
| 20.04 LTS focal |
Fixed 1:4.1.45-1ubuntu0.1~esm6
|
|
| 18.04 LTS bionic |
Fixed 1:4.1.7-4ubuntu0.1+esm6
|
|
| 14.04 LTS trusty |
Fixed 1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1
|
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| Parameter | Value |
|---|---|
| Base score |
5.8 · Medium
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Changed |
| Confidentiality | None |
| Integrity impact | Low |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N |
References
Related Ubuntu Security Notices (USN)
- USN-8401-1
- Netty vulnerabilities
- 8 June 2026