CVE-2026-116542

Netty netty-tcnative before 2.0.84.Final SNI Hostname Spoofing via Modified UTF-8 Decoding

MEDIUM
5.3
CVSS Score
Published: October 26, 2026 at 02:59 PM UTC
Updated: October 31, 2026 at 02:17 AM UTC
2 products affected across 1 vendornetty-tcnativenetty-tcnative-boringssl-static

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.2%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-176

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