{"id":"CVE-2026-116539","title":"Netty netty-tcnative before 2.0.84.Final Heap Buffer Overflow via OpenSSL BIO","summary":"Netty netty-tcnative before 2.0.84.Final contains a heap buffer overflow vulnerability in the tcn_write_to_bytebuffer BIO callback caused by failing to wrap the non-application ring buffer write index. Remote TLS peers can drive handshak…","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-787"],"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":"2026-10-26T14:59:39.460Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-116539","references":[{"url":"https://github.com/netty/netty-tcnative/security/advisories/GHSA-gf9q-9mg7-g5qh","label":"GitHub Security Advisory (GHSA-gf9q-9mg7-g5qh)"},{"url":"https://github.com/netty/netty-tcnative/commit/92dd66fd1243d85c05a61288f96367a70260b6b8","label":"Patch Commit"},{"url":"https://github.com/netty/netty-tcnative/blob/netty-tcnative-parent-2.0.83.Final/openssl-dynamic/src/main/c/ssl.c#L199"},{"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-heap-buffer-overflow-via-openssl-bio","label":"VulnCheck Advisory: Netty netty-tcnative before 2.0.84.Final Heap Buffer Overflow via OpenSSL BIO"}],"tags":["cve.org"],"ingestedAt":"2026-10-26T15:29:30.504Z","slug":"CVE-2026-116539","body":"## Overview\n\nNetty netty-tcnative before 2.0.84.Final contains a heap buffer overflow vulnerability in the tcn_write_to_bytebuffer BIO callback caused by failing to wrap the non-application ring buffer write index. Remote TLS peers can drive handshake, renegotiation, or post-handshake messages into this buffer, triggering an out-of-bounds memcpy that crashes the JVM process.\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":32,"depthScoreParts":{"impact":32.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}