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
Source GCVE Database
Not known to be exploited · CVSS 6.9 Medium : upgrade to 2.0.84.Final when convenient.
Data as of 26 Oct 2026, 19:44 UTC
- Patch
- Available – fixed in 2.0.84.Final
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 26 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade netty-tcnative and netty-tcnative-boringssl-static and netty/io.netty:netty-tcnative and netty/io.netty:netty-tcnative-boringssl-static to 2.0.84.Final.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| netty-tcnativeio.netty:netty-tcnative | Affected
| Fixed in
|
| netty-tcnative-boringssl-staticio.netty:netty-tcnative-boringssl-static | Affected
| Fixed in
|
Mavennetty/io.netty:netty-tcnativepkg:maven/netty/io.netty:netty-tcnativeOther threats | Affected
| Fixed in
|
Mavennetty/io.netty:netty-tcnative-boringssl-staticpkg:maven/netty/io.netty:netty-tcnative-boringssl-staticOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
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.
References
- github.com/netty/netty-tcnative/security/advisories/GHSA-2784-hxmm-4hgf (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-116542 (opens in a new tab)
- github.com/netty/netty-tcnative/commit/a879c85b9776cf478aada3ca69e60b8c0a99ed38 (opens in a new tab)
- github.com/netty/netty-tcnative (opens in a new tab)
- github.com/netty/netty-tcnative/blob/netty-tcnative-parent-2.0.83.Final/openssl-dynamic/src/main/c/sslcontext.c (opens in a new tab)
- github.com/netty/netty-tcnative/releases/tag/netty-tcnative-parent-2.0.84.Final (opens in a new tab)
- vulncheck.com/advisories/netty-netty-tcnative-before-2.0.84-final-sni-hostname-spoofing-via-modified-utf-8-decoding (opens in a new tab)