CVE-2026-93578

NameCVE-2026-93578
DescriptionA 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certificate revocation checks, allowing applications using Netty's OCSP Client to accept certificates that should have been revoked, leading to an authorization bypass.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs1148396

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
netty (PTS)bookworm, bookworm (security)1:4.1.48-7+deb12u2vulnerable
trixie (security), trixie1:4.1.48-10+deb13u1vulnerable
forky, sid1:4.1.48-16vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
nettysource(unstable)(unfixed)1148396

Notes

https://bugzilla.redhat.com/show_bug.cgi?id=2536969
https://github.com/netty/netty/security/advisories/GHSA-jhjp-5q4f-8wr2

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