CVE-2026-56821
CVE-2026-56821 updated by NVD
Summary
Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, the OcspServerCertificateValidator flags an out-of-date OCSP response but does not stop processing it, so an expired GOOD response is still reported as VALID, letting an on-path attacker replay a stale GOOD response to bypass revocation of a since-revoked certificate. Exploitation can lead to certificate revocation bypass via replay of an expired OCSP response. Any application using OcspServerCertificateValidator is affected; a revoked certificate can be accepted. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.
Affected packages
| Ecosystem | Package | Affected versions | Fixed versions |
|---|---|---|---|
| Maven | io.netty:netty-handler-ssl-ocsp | — | 4.2.16.Final, 4.1.136.Final |
Remediation: Upgrade to 4.2.16.Final or later.
References
Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.
Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.
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