Traffic disclosure via skipped TLS hostname verification
Published Aug 22, 2026 · Updated Aug 22, 2026
Certificate validation bypass in Netty through 4.1.136.Final and 4.2.0.Final through 4.2.16.Final allows man-in-the-middle attackers to read traffic. On the SslProvider.OPENSSL client path, OpenSslX509TrustManagerWrapper returns a plain X509TrustManager unchanged when Unsafe-based wrapping is unavailable, so the peer hostname is never checked against the certificate. Exploitation requires Java 25 or later, the OpenSSL provider, a non-extended trust manager, and control of the TLS network path; the advisory identifies confidentiality as the only impact.
Summary
What happened
Certificate validation bypass in Netty through 4.1.136.Final and 4.2.0.Final through 4.2.16.Final allows man-in-the-middle attackers to read traffic. On the SslProvider.OPENSSL client path, OpenSslX509TrustManagerWrapper returns a plain X509TrustManager unchanged when Unsafe-based wrapping is unavailable, so the peer hostname is never checked against the certificate. Exploitation requires Java 25 or later, the OpenSSL provider, a non-extended trust manager, and control of the TLS network path; the advisory identifies confidentiality as the only impact.
The record
- CVE
- CVE-2026-62243
- Published
- Aug 22, 2026
- Updated
- Aug 22, 2026
- Vendor
- The Netty Project
- Product
- Netty
- Classifications
- CWE-297, T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 22, 2026CVE publishedPublication date reported by the CVE source.
- Aug 22, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <4.1.137.Final
- Affected versionversion=4.2.0.Final <4.2.16.Final
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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