Answer in brief
CVE-2026-45416 records a High severity (CVSS 7.5) vulnerability in Netty: SNI handler pre-allocates up to 16 MiB from nine attacker bytes. The current sources do not mark it as known exploited. The current feed maps netty/netty (generic), io.netty:netty-handler (maven), io.netty:netty-handler (maven). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps netty/netty (generic), io.netty:netty-handler (maven), io.netty:netty-handler (maven). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| netty/nettygeneric | >= 4.2.0.Final, < 4.2.15.Final || < 4.1.135.Final | Not reported |
| io.netty:netty-handlermaven | >=4.2.0.Final,<=4.2.14.Final | 4.2.15.Final |
| io.netty:netty-handlermaven | <=4.1.134.Final | 4.1.135.Final |
Published upstream
Jun 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 11, 2026
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, 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. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Quoted source text, attributed separately from HOL analysis.