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 handshake, renegotiation, or post-handshake messages into this buffer, triggering an out-of-bounds memcpy that crashes the JVM process.
https://github.com/netty/netty-tcnative/security/advisories/GHSA-gf9q-9mg7-g5qh
https://github.com/netty/netty-tcnative/releases/tag/netty-tcnative-parent-2.0.84.Final
https://github.com/netty/netty-tcnative/commit/92dd66fd1243d85c05a61288f96367a70260b6b8
Published: 2026-10-26
Updated: 2026-10-26
Base Score: 5.4
Vector: CVSS2#AV:N/AC:H/Au:N/C:N/I:N/A:C
Severity: Medium
Base Score: 5.9
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: Medium
Base Score: 8.2
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00396