Bug 2445762 (CVE-2026-3832)

Summary:	CVE-2026-3832 gnutls: gnutls: Security bypass allows acceptance of revoked server certificates via crafted OCSP response
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	kshier, mcascell, rhel-process-autobot, saroy, security-response-team, stcannon, teagle, watson-tool-maintainers, yguenane
Target Milestone:	---	Keywords:	Security
Target Release:	---	Flags:	mcascell: needinfo?
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in gnutls. A remote attacker could exploit this vulnerability by presenting a specially crafted Online Certificate Status Protocol (OCSP) response during a TLS handshake. Due to a logic error in how gnutls processes multi-record OCSP responses, a client with OCSP verification enabled may incorrectly accept a revoked server certificate, potentially leading to a compromise of trust.	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 2026-03-09 13:57:29 UTC

gnutls matches a stapled ocsp response to the server certificate by scanning SingleResponse records, but then reads cert_status from record index 0 unconditionally. when a multi-record ocsp response is stapled such that record 0 is for a different certificate (good) and the matching record for the server certificate is later (revoked), a client with ocsp verification enabled can accept a revoked server certificate. this is observable as an order-dependent accept/reject outcome for the same revoked server certificate.

Comment 5 errata-xmlrpc 2026-06-16 16:39:17 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:26409 https://access.redhat.com/errata/RHSA-2026:26409