CVE-2026-56821
Description
A flaw was found in netty-handler-ssl-ocsp, a component of the Netty network application framework. The Online Certificate Status Protocol (OCSP) stapling validator in this component does not properly check certificate revocation status. This can allow an attacker to use revoked certificates without detection, potentially compromising secure communications.
Statement
Moderate: The netty-handler-ssl-ocsp component, integrated into Red Hat products, is affected by an improper certificate revocation check within its OCSP stapling validator. This flaw could enable an attacker to successfully employ revoked certificates, bypassing detection and potentially compromising the security of communications in applications that rely on this functionality.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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 | 5.7 | N/A | 7.4 |
| Attack Vector | Adjacent Network | N/A | Network |
| Attack Complexity | Low | N/A | High |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Application Data
Frequently Asked Questions
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