CVE-2026-42580: netty · HTTP Request/Response Smuggling
Affects nettySource GCVE Database
Not known to be exploited · CVSS 6.5 Medium : upgrade to 4.2.13.Final or 4.1.133.Final when convenient.
Data as of 26 Oct 2026, 18:27 UTC
- Patch
- Available – fixed in 4.2.13.Final, 4.1.133.Final
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:LExploitation evidence
Disclosed: evidence found.
CVE published 13 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade netty to 4.2.13.Final or 4.1.133.Final.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| netty netty | Affected
| Fixed in
|
AI-suggested
Upgrade Netty to version 4.2.13.Final or later, or 4.1.133.Final or later, where this vulnerability has been fixed. No other mitigation is indicated by the vendor advisory.
Description
CVE-2026-42580 is a medium severity vulnerability in Netty, an asynchronous network application framework. The issue involves an integer overflow in the chunk size parser prior to versions 4.2.13.Final and 4.1.133.Final, which enables HTTP request/response smuggling attacks. This vulnerability has been fixed in the specified versions.