Bug 2505982 (CVE-2026-56820)

Summary:	CVE-2026-56820 io.netty/netty-handler-ssl-ocsp: Netty: Certificate revocation bypass via OCSP response replay attack
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	anujha, asoldano, bbaranow, bmaxwell, bstansbe, dlofthou, fmariani, gmalinko, istudens, ivassile, iweiss, janstey, jwon, mcarlett, mosmerov, msvehla, nwallace, pberan, pesilva, pjindal, pmackay, rstancel, rstepani, tcunning, thjenkin, vdosoudi, yfang
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in Netty. The `OcspClient` component fails to validate that the Certificate ID in an Online Certificate Status Protocol (OCSP) response matches the requested Certificate ID. This vulnerability allows a remote attacker to bypass certificate revocation checks by presenting a legitimately signed OCSP response for an unrelated certificate issued by the same Certificate Authority, leading to a replay attack. This can result in the acceptance of revoked certificates, potentially compromising the integrity and confidentiality of communications.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-07-21 23:04:13 UTC

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.

Comment 1 errata-xmlrpc 2026-08-13 14:51:43 UTC

This issue has been addressed in the following products:

  Red Hat build of Apache Camel 4.18.3 for Spring Boot 3.5.16

Via RHSA-2026:54622 https://access.redhat.com/errata/RHSA-2026:54622

Comment 2 Jon Orris 2026-09-21 12:20:29 UTC

This issue has been addressed in the following products:

  Red Hat Data Grid 8.6.3

Via RHSA-2026:69296 https://access.redhat.com/errata/RHSA-2026:69296