Vulnerability in Netty Netty-Tcnative
CVE-2026-116542
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 the ClientHello server_name to confuse SNI-based certificate selection, access decisions, and logging.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/netty/netty-tcnative/security/advisories/GHSA-2784-hxmm-4hgf (vendor-advisory)
- github.com/netty/netty-tcnative/commit/a879c85b9776cf478aada3ca69e60b8c0a99ed38 (patch)
- github.com/netty/netty-tcnative/blob/netty-tcnative-parent-2.0.83.Final/openssl… (technical-description)
- github.com/netty/netty-tcnative/releases/tag/netty-tcnative-parent-2.0.84.Final (release-notes)
- github.com/netty/netty-tcnative (product)
- www.vulncheck.com/advisories/netty-netty-tcnative-before-2.0.84-final-sni-hostn… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-116542?
- CVE-2026-116542 is a medium-severity vulnerability in Netty Netty-Tcnative, classified under CWE-176. CVSS score: 5.3/10. Published 2026-10-26.
- How severe is CVE-2026-116542?
- Medium severity. CVSS v3 base score is 5.3 out of 10.