{"cve":"CVE-2026-45416","nvd":{"published":"2026-06-12T15:16:26.940","modified":"2026-09-18T13:18:25.647","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-770"],"references":["https://github.com/netty/netty/releases/tag/netty-4.1.135.Final","https://github.com/netty/netty/releases/tag/netty-4.2.15.Final","https://github.com/netty/netty/security/advisories/GHSA-x4gw-5cx5-pgmh","https://access.redhat.com/errata/RHSA-2026:26017","https://access.redhat.com/errata/RHSA-2026:26018"],"products":["netty:netty"],"source":"nvd","synced_at":"2026-10-19T22:38:48.522727527+00:00"},"epss":{"cve":"CVE-2026-45416","score":0.00921,"percentile":0.60317,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-x4gw-5cx5-pgmh","url":"https://osv.dev/vulnerability/GHSA-x4gw-5cx5-pgmh","summary":"Netty: SNI handler pre-allocates up to 16 MiB from nine attacker bytes","modified":"2026-09-10T03:50:12.401611631Z","packages":[{"ecosystem":"Maven","name":"io.netty:netty-handler","purl":"pkg:maven/io.netty/netty-handler","ranges":[">=4.2.0.Final <4.2.15.Final"],"fixed":["4.2.15.Final"]},{"ecosystem":"Maven","name":"io.netty:netty-handler","purl":"pkg:maven/io.netty/netty-handler","ranges":["<4.1.135.Final"],"fixed":["4.1.135.Final"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}