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Fencer Vulns
medium 5.9

CVE-2026-93578 json

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

published 2026-09-18 51 d ago modified 2026-09-18 51 d ago also EUVD-2026-82871

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 13%
public exploits
0
none known

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certificate revocation checks, allowing applications using Netty's OCSP Client to accept certificates that should have been revoked, leading to an authorization bypass.

Patch / fix

  • netty-tcnative SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 2.0.84-150200.3.51.1
  • netty SLE Module for Package Hub 15 SP7 4.1.138-150200.4.56.1

suse advisories SUSE-SU-2026:4391-1

  • netty openSUSE Tumbleweed 4.1.138-1.1

opensuse advisories openSUSE-SU-2026:11882-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-93578 updated cvss 5.9

io.netty/netty-handler-ssl-ocsp: Netty: Missing Extended Key Usage (EKU) check in OCSP Client allows certificate revocation bypass

  • Red Hat build of Apache Camel for Spring Boot 4 netty-handler-ssl-ocsp 4.1.136.Final-redhat-00001
    affected: workaround, no fix available “See https://github.com/netty/netty/security/advisories/GHSA-jhjp-5q4f-8wr2 for fixed versions and remediation guidance.”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
51 d ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • access.redhat.com https://access.redhat.com/security/cve/CVE-2026-93578 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

  • Red Hat Red Hat build of Apache Camel for Spring Boot 4

Classification

Weakness
  • CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
Technology feeds

References

Sources

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