CVE-2026-62243

High

Description

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.

SeverityHigh

CVSS7.5

Exploit probability—

ProductNetty

PublishedAug 22, 2026

First seenAug 22, 2026

Weakness typeCWE-297CWE-297

How to fix

Update

netty netty4.2.16.Final, 4.1.137.Final or later

Vendor advisories

github.com/netty/netty/security/advisories/GHSA-p85m-gvr3-788c

Affected products

Product	Affected versions	Fixed in
netty netty	4.2.0.Final ≤ v < 4.2.16.Final, v < 4.1.137.Final	4.2.16.Final, 4.1.137.Final

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.