CVE-2026-93578

Summary

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certificate revocation checks, allowing applications using Netty's OCSP Client to accept certificates that should have been revoked, leading to an authorization bypass.

Affected Software

VendorProductVersion RangeStatus

Weaknesses

  • CWE-1035: CWE-1035

Workarounds

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

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: partial

Additional References

References