GHSA-x4gw-5cx5-pgmh
Netty: SNI handler pre-allocates up to 16 MiB from nine attacker bytes
At a glance
- Published
- Updated
- CVE
- CVE-2026-45416
- CVSS_V3
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Description
SslClientHelloHandler.decode() reads the 24-bit TLS handshake length and, when the ClientHello does not fit in the first record, eagerly allocates `ctx.alloc().buffer(handshakeLength)` (line 161). The guard at line 140 is `handshakeLength > maxClientHelloLength && maxClientHelloLength != 0`, and the commonly-used SniHandler/AbstractSniHandler constructors (SniHandler(Mapping), SniHandler(AsyncMapping), AbstractSniHandler()) pass maxClientHelloLength=0 and handshakeTimeoutMillis=0, so the length guard is disabled and no timeout is scheduled. A 16 MiB request exceeds the default pooled chunk size and becomes a huge/unpooled allocation performed immediately. The buffer is retained in the handler until the channel closes.
Affected packages
| Package | Versions |
|---|---|
| Maven · io.netty:netty-handler | introduced 4.2.0.Final, fixed 4.2.15.Final |
| Maven · io.netty:netty-handler | introduced 0, fixed 4.1.135.Final |
References
- https://github.com/netty/netty/security/advisories/GHSA-x4gw-5cx5-pgmh WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-45416 ADVISORY
- https://github.com/netty/netty PACKAGE
- https://github.com/netty/netty/releases/tag/netty-4.1.135.Final WEB
- https://github.com/netty/netty/releases/tag/netty-4.2.15.Final WEB
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |