CVE-2026-116542
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AI Threat Summary
CVE-2026-116542 is a moderate vulnerability with a CVSS score of 5.3 affecting the target software. Authentication can be bypassed allowing unauthenticated access. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.
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.
Attack Chain
Attacker identifies authentication endpoint and tests for bypass conditions
Attacker exploits CVE-2026-116542 authentication flaw to gain unauthorized access without valid credentials
Attacker enumerates accessible resources, users, and configurations
Attacker exfiltrates sensitive data accessible without proper authorization
MITRE ATT&CK Techniques
Indicators of Compromise
| Type | Value | Description | |
|---|---|---|---|
| user_agent | Mozilla/5.0 (compatible; exploit/1.0) |
Generic exploit scanner user agent pattern | |
| url | /api/vuln-endpoint?payload=<malicious> |
Exploit attempt against application endpoint — monitor access logs for anomalous params |
Remediation
Quick Facts
| CVE ID | CVE-2026-116542 |
| CVSS Score | 5.3 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| Published | 2026-10-26 |
| Exploited | No |
| CISA KEV | No |
| PoC | Not public |
References
- https://github.com/netty/netty-tcnative
- https://github.com/netty/netty-tcnative/blob/netty-tcnative-…
- https://github.com/netty/netty-tcnative/commit/a879c85b9776c…
- https://github.com/netty/netty-tcnative/releases/tag/netty-t…
- https://github.com/netty/netty-tcnative/security/advisories/…
- https://www.vulncheck.com/advisories/netty-netty-tcnative-be…