{"id":"CVE-2026-116542","title":"Netty netty-tcnative before 2.0.84.Final SNI Hostname Spoofing via Modified UTF-8 Decoding","summary":"Netty netty-tcnative before 2.0.84.Final contains an SNI hostname spoofing vulnerability that allows remote unauthenticated clients to alter hostnames via JNI NewStringUTF decoding. Attackers can send overlong encodings like 0xC0 0x80 in…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","cvssSource":"cna","cwe":["CWE-176"],"vendor":"netty","product":"io.netty:netty-tcnative","affected":["io.netty:netty-tcnative < 2.0.84.Final","io.netty:netty-tcnative-boringssl-static < 2.0.84.Final"],"published":"2026-10-26","updated":"2026-10-26","sourceUpdated":"2026-10-26T14:59:41.528Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-116542","references":[{"url":"https://github.com/netty/netty-tcnative/security/advisories/GHSA-2784-hxmm-4hgf","label":"GitHub Security Advisory (GHSA-2784-hxmm-4hgf)"},{"url":"https://github.com/netty/netty-tcnative/commit/a879c85b9776cf478aada3ca69e60b8c0a99ed38","label":"Patch Commit"},{"url":"https://github.com/netty/netty-tcnative/blob/netty-tcnative-parent-2.0.83.Final/openssl-dynamic/src/main/c/sslcontext.c#L2608"},{"url":"https://github.com/netty/netty-tcnative/releases/tag/netty-tcnative-parent-2.0.84.Final","label":"netty-tcnative netty-tcnative-parent-2.0.84.Final Release Notes"},{"url":"https://github.com/netty/netty-tcnative"},{"url":"https://www.vulncheck.com/advisories/netty-netty-tcnative-before-2.0.84-final-sni-hostname-spoofing-via-modified-utf-8-decoding","label":"VulnCheck Advisory: Netty netty-tcnative before 2.0.84.Final SNI Hostname Spoofing via Modified UTF-8 Decoding"}],"tags":["cve.org"],"ingestedAt":"2026-10-26T15:29:30.502Z","slug":"CVE-2026-116542","body":"## Overview\n\nNetty netty-tcnative before 2.0.84.Final contains an SNI hostname spoofing vulnerability that allows remote unauthenticated clients to alter hostnames via JNI NewStringUTF decoding. Attackers can send overlong encodings like 0xC0 0x80 in the ClientHello server_name to confuse SNI-based certificate selection, access decisions, and logging.\n\n## Affected\n\n- `io.netty:netty-tcnative < 2.0.84.Final`\n- `io.netty:netty-tcnative-boringssl-static < 2.0.84.Final`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}