Vulnerability in Red Hat Certificate System 10

CVE-2026-78323

A flaw was found in JSS (Java Security Services). The JSSTrustManager class does not verify NSS trust flags when validating CA certificates, allowing certificates present in the NSS database without TRUSTED_CA flags to be accepted as trust anchors for TLS connections. In non-default configurations where certificate revocation checking is disabled, this could allow a man-in-the-middle attacker to forge certificates accepted by PKI client connections.

Vulnerability class: Improper Certificate Validation

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (6.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 6.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-78323: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-78323?
CVE-2026-78323 is a medium-severity vulnerability in Red Hat Certificate System 10, classified under Improper Certificate Validation. CVSS score: 6.5/10. Published 2026-08-24.
How severe is CVE-2026-78323?
Medium severity. CVSS v3 base score is 6.5 out of 10.