CVE-2026-116542
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk11th percentile - higher than 11% of all known CVEs
Summary
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.
Risk Assessment
An attacker can bypass SNI-based certificate selection and access controls and poison logs, potentially leading to unauthorized access or incorrect client identification.
Recommendation
Upgrade netty-tcnative to version 2.0.84.Final or later.
Other vulnerabilities in netty-tcnative
See all- CVE-2026-116541Medium
Netty netty-tcnative before 2.0.84.Final contains a denial of service vulnerability in the tcn_write_to_bytebuffer BIO write callback that overreports bytes consumed. Remote TLS 1.3 peers can provoke queued post-handshake records like NewSessionTicket or KeyUpdate to truncate flights, fail connections, or abort the JVM process.
- CVE-2026-116540Medium
netty-tcnative 2.0.66.Final before 2.0.84.Final built against OpenSSL 3.x contains a use-after-free vulnerability in ssl_tlsext_ticket_key_cb during session ticket key rotation. Remote clients performing TLS handshakes while setSessionTicketKeys0 frees the shared key array cause OpenSSL to read freed HMAC keys, crashing or corrupting ticket processing.
- CVE-2026-116539Medium
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.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS