Netty prior 4.2.17.Final/4.1.137.Final SslProvider certificate host validation

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k1.34

Summaryinfo

A vulnerability was found in Netty. It has been classified as problematic. This impacts an unknown function of the component SslProvider. This manipulation causes certificate host validation. This vulnerability is registered as CVE-2026-62243. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in Netty. It has been declared as problematic. Affected by this vulnerability is an unknown code block of the component SslProvider. The manipulation with an unknown input leads to a certificate host validation vulnerability. The CWE definition for the vulnerability is CWE-297. The product communicates with a host that provides a certificate, but the product does not properly ensure that the certificate is actually associated with that host. As an impact it is known to affect integrity. The summary by CVE is:

Netty (io.netty:netty-handler) versions from 4.2.0.Final through 4.2.16.Final and versions through 4.1.136.Final disable TLS hostname verification on the SslProvider.OPENSSL client path when a plain (non-extended) X509TrustManager is used and Unsafe-based trust-manager wrapping is unavailable (Java 25+). In this configuration the OpenSSL client does not perform hostname verification, allowing a man-in-the-middle attacker to present a certificate issued for a different hostname that is accepted without validation. Fixed in 4.2.17.Final and 4.1.137.Final.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-62243 since 07/13/2026. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1587.003 according to MITRE ATT&CK.

Upgrading to version 4.2.17.Final or 4.1.137.Final eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (VulnCheck): 🔒

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Certificate host validation
CWE: CWE-297 / CWE-295 / CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Netty 4.2.17.Final/4.1.137.Final

Timelineinfo

07/13/2026 CVE reserved
08/22/2026 +40 days Advisory disclosed
08/22/2026 +0 days VulDB entry created
08/22/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-62243 (🔒)
GCVE (CVE): GCVE-0-2026-62243
GCVE (VulDB): GCVE-100-394315

Entryinfo

Created: 08/22/2026 15:01
Changes: 08/22/2026 15:01 (74)
Complete: 🔍
Cache ID: 216::103

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