CVE-2026-116539: netty-tcnative · Out-of-bounds Write
Affects netty-tcnativeSource CVE Database V5
Not known to be exploited · CVSS 8.2 High : upgrade to 2.0.84.Final soon.
Data as of 26 Oct 2026, 17:30 UTC
- Patch
- Available – fixed in 2.0.84.Final
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/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.
AI-suggested
Upgrade netty-tcnative to version 2.0.84.Final or later, where this vulnerability is fixed. No other mitigation or temporary workaround is indicated.
Description
CVE-2026-116539 is a heap buffer overflow vulnerability in netty-tcnative before version 2.0.84.Final. It occurs in the tcn_write_to_bytebuffer BIO callback due to improper handling of the ring buffer write index. Remote TLS peers can exploit this during handshake, renegotiation, or post-handshake messages to trigger an out-of-bounds memory copy, causing the JVM process to crash.
References
- github.com/netty/netty-tcnative/security/advisories/GHSA-gf9q-9mg7-g5qh (opens in a new tab)
- github.com/netty/netty-tcnative/commit/92dd66fd1243d85c05a61288f96367a70260b6b8 (opens in a new tab)
- github.com/netty/netty-tcnative/blob/netty-tcnative-parent-2.0.83.Final/openssl-dynamic/src/main/c/ssl.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)
- github.com/netty/netty-tcnative (opens in a new tab)
- vulncheck.com/advisories/netty-netty-tcnative-before-2.0.84-final-heap-buffer-overflow-via-openssl-bio (opens in a new tab)