A flaw was found in Netty's Online Certificate Status Protocol (OCSP) Client. (CVE-2026-93578)
A vulnerability in Netty's Online Certificate Status Protocol (OCSP) Client allows bypassing certificate revocation checks. The client does not verify the 'id-kp-OCSPSigning' Extended Key Usage in OCSP responder certificates. This flaw enables a remote attacker with any valid certificate from the same CA to forge 'GOOD' OCSP responses for revoked certificates, potentially causing authorization bypass in applications using the affected Netty versions.
AI Analysis
Technical Summary
Netty's OCSP Client fails to verify the 'id-kp-OCSPSigning' Extended Key Usage in OCSP responder certificates. This allows a remote attacker, possessing any valid certificate issued by the same Certificate Authority, to forge positive OCSP responses for certificates that have been revoked. As a result, applications relying on Netty's OCSP Client may accept revoked certificates, leading to an authorization bypass vulnerability.
Potential Impact
The vulnerability allows attackers to bypass certificate revocation checks by forging OCSP responses indicating revoked certificates are valid. This can lead to authorization bypass in applications using the affected Netty OCSP Client versions, potentially allowing unauthorized access or actions.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should monitor vendor communications for updates and consider alternative certificate validation methods if feasible.
A flaw was found in Netty's Online Certificate Status Protocol (OCSP) Client. (CVE-2026-93578)
Description
A vulnerability in Netty's Online Certificate Status Protocol (OCSP) Client allows bypassing certificate revocation checks. The client does not verify the 'id-kp-OCSPSigning' Extended Key Usage in OCSP responder certificates. This flaw enables a remote attacker with any valid certificate from the same CA to forge 'GOOD' OCSP responses for revoked certificates, potentially causing authorization bypass in applications using the affected Netty versions.
CVSS v3.1
Score 5.9medium
Affected software
pkg:deb/ubuntu/netty?arch=source&distro=esm-infra-legacy/trustypkg:deb/ubuntu/netty?arch=source&distro=esm-apps-legacy/xenialpkg:deb/ubuntu/netty?arch=source&distro=esm-apps/bionicpkg:deb/ubuntu/netty?arch=source&distro=esm-apps/focalpkg:deb/ubuntu/netty?arch=source&distro=esm-apps/jammypkg:deb/ubuntu/netty?arch=source&distro=esm-apps/noblepkg:deb/ubuntu/netty?arch=source&distro=esm-apps/resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Netty's OCSP Client fails to verify the 'id-kp-OCSPSigning' Extended Key Usage in OCSP responder certificates. This allows a remote attacker, possessing any valid certificate issued by the same Certificate Authority, to forge positive OCSP responses for certificates that have been revoked. As a result, applications relying on Netty's OCSP Client may accept revoked certificates, leading to an authorization bypass vulnerability.
Potential Impact
The vulnerability allows attackers to bypass certificate revocation checks by forging OCSP responses indicating revoked certificates are valid. This can lead to authorization bypass in applications using the affected Netty OCSP Client versions, potentially allowing unauthorized access or actions.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should monitor vendor communications for updates and consider alternative certificate validation methods if feasible.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-93578
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:Pro:14.04:LTS","Ubuntu:Pro:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:Pro:22.04:LTS","Ubuntu:Pro:24.04:LTS","Ubuntu:Pro:26.04:LTS"]
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ab4be2df7a7c54106eeec14
Added to database: 09/24/2026, 06:07:41 UTC
Last enriched: 09/24/2026, 06:25:11 UTC
Last updated: 09/25/2026, 02:47:33 UTC
Views: 3
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