5.9

CVE-2026-93578: netty

CVSS: 5.9v3.1MediumAwaiting analysis
AliasesUBUNTU-CVE-2026-93578DEBIAN-CVE-2026-93578
Published 18-09-2026Last modified 18-09-2026
Open JSON

Vulnerability summary

CVE-2026-93578 is a medium (CVSS 5.9) vulnerability in netty. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 12.4% of scored vulnerabilities.

Overall risk
24/100
0100
Low · default modelHow is this calculated?
CVSS score
5.9/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.23%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 2
OPENSUSE-SU-2026:11882-1SUSE-SU-2026:4391-1

Timeline

  1. 18-09-2026
    PublishedVulnerability first disclosed.
  2. 18-09-2026
    Last modifiedVulnerability information updated.

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certificate revocation checks, allowing applications using Netty's OCSP Client to accept certificates that should have been revoked, leading to an authorization bypass.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.23%

Chance of exploitation in the next 30 days

Percentile

12%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

19-09-202618-10-2026
EPSS score
0.23%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • nettyAll versions (No fix recorded)
Ubuntu1 product
  • nettyAll versions (No fix recorded)

2 vendors · 2 products

References

6 links