CVE-2026-93578

Io.netty/netty-handler-ssl-ocsp: netty: missing extended key usage (eku) check in ocsp client allows certificate revocation bypass

Published Sep 18, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
Description
A flaw was found in Netty's Online Certificate Status Protocol (OCSP) Client. The client fails to verify the 'id-kp-OCSPSigning' Extended Key Usage (EKU) in OCSP responder certificates. A remote attacker, holding any valid certificate issued by the same Certificate Authority (CA), can exploit this by forging 'GOOD' OCSP responses for revoked certificates. This bypasses certificate revocation checks, allowing applications using Netty's OCSP Client to accept certificates that should have been revoked, leading to an authorization bypass.

Remediation

Vendor Workaround

See https://github.com/netty/netty/security/advisories/GHSA-jhjp-5q4f-8wr2 for fixed versions and remediation guidance.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Io.netty
Io.netty netty-codec-http
Redhat build Of Apache Camel For Spring Boot
Vendors & Products Io.netty
Io.netty netty-codec-http
Redhat build Of Apache Camel For Spring Boot
Type Values Removed Values Added
Description Missing Extended Key Usage (EKU) check in OCSP Client allows certificate revocation bypass A flaw was found in Netty's Online Certificate Status Protocol (OCSP) Client. The client fails to verify the 'id-kp-OCSPSigning' Extended Key Usage (EKU) in OCSP responder certificates. A remote attacker, holding any valid certificate issued by the same Certificate Authority (CA), can exploit this by forging 'GOOD' OCSP responses for revoked certificates. This bypasses certificate revocation checks, allowing applications using Netty's OCSP Client to accept certificates that should have been revoked, leading to an authorization bypass.
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Netty: netty-handler-ssl-ocsp: io.netty/netty-handler-ssl-ocsp: netty: missing extended key usage (eku) check in ocsp client allows certificate revocation bypass Io.netty/netty-handler-ssl-ocsp: netty: missing extended key usage (eku) check in ocsp client allows certificate revocation bypass
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N'}

Type Values Removed Values Added
Description Missing Extended Key Usage (EKU) check in OCSP Client allows certificate revocation bypass
Title Netty: netty-handler-ssl-ocsp: io.netty/netty-handler-ssl-ocsp: netty: missing extended key usage (eku) check in ocsp client allows certificate revocation bypass
First Time appeared Redhat
Redhat camel Spring Boot
Weaknesses CWE-1035
CPEs cpe:/a:redhat:camel_spring_boot:4
Vendors & Products Redhat
Redhat camel Spring Boot
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Sep 18, 2026, 4:54 PM
Reserved
Sep 18, 2026, 10:34 AM
Status
Awaiting Analysis
Published
Sep 18, 2026, 11:17 AM
Modified
Sep 18, 2026, 7:06 PM
Severity
Moderate
Public date
Sep 10, 2026, 12:54 AM