CVE-2026-56821

Published: Lug 29, 2026 Last Modified: Lug 29, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 7,4
Source: [email protected]
Attack Vector: network
Attack Complexity: high
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: none

Description

AI Translation Available

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 Prior to versions 4.1.136.Final and 4.2.16.Final, the OcspServerCertificateValidator flags an out-of-date OCSP response but does not stop processing it, so an expired GOOD response is still reported as VALID, letting an on-path attacker replay a stale GOOD response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.

299

Improper Check for Certificate Revocation

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Access Control Integrity Other Confidentiality
Potential Impacts:
Gain Privileges Or Assume Identity Other Read Application Data
Applicable Platforms
Technologies: Not Technology-Specific, Web Based
Likelihood of Exploit: Medium
View CWE Details
https://github.com/netty/netty/security/advisories/GHSA-g7h…
https://github.com/netty/netty/security/advisories/GHSA-g7hg-vrcf-mvmr