CVE-2026-78323
Description
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.
Statement
This flaw exists in the JSSTrustManager class but is mitigated in default product configurations by the native revocation verification check. Exploitation requires non-default configuration changes (disabling certificate revocation verification) that are not documented or recommended. The server-side TLS validation path (TomcatJSS) uses a different trust manager (JSSNativeTrustManager) that properly delegates to NSS native verification and is not affected.
Mitigation
In default configurations, this flaw is mitigated by the native revocation verification check (certChainRevokeVerify) which is enabled by default on PKI client connections. Ensure that certificate revocation verification remains enabled (do not set isCertRevocationVerify to false). On the server side, the default TomcatJSS configuration uses JSSNativeTrustManager which is not affected by this flaw.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | 6.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
Understanding the Weakness (CWE)
Integrity,Authentication
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity
When a certificate is invalid or malicious, it might allow an attacker to spoof a trusted entity by interfering in the communication path between the host and client. The product might connect to a malicious host while believing it is a trusted host, or the product might be deceived into accepting spoofed data that appears to originate from a trusted host.
Acknowledgements
This issue was discovered by Marco Fargetta (Red Hat).
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