CVE-2026-56820 — Netty: Missing CertificateID Validation in OCSP Response Allows Replay Attacks
Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and prior to 4.1.135.Final, `OcspClient` d…
Published: 2026-07-21 · CVSS: 7.4 · CVSS 3.1
Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and prior to 4.1.135.Final, `OcspClient` does not validate that the `CertificateID` in an OCSP response matches the requested `CertificateID`, which can lead to replay attack. `OcspClient.validateResponse` accepts a legitimately signed `GOOD` status response for an unrelated certificate issued by the same CA, allowing bypass of revocation checks for another certificate. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7