CVE-2026-68453
Description
A flaw was found in the Linux kernel's s390/zcrypt component. This vulnerability arises from insufficient validation of user-controlled length fields within the Common Cryptographic Architecture (CCA) token structures. An attacker could manipulate these fields to cause a buffer over-read or under-run. This could lead to a kernel crash, resulting in a denial of service, or the exposure of sensitive memory information.
Statement
This vulnerability is classified with a Moderate severity because exploitation requires authenticated local access to the cryptographic driver interface on IBM Z (s390x) systems, restricting the overall blast radius. While a local user with access to protected key operations can induce an out-of-bounds memory read to trigger an operating system crash or potentially disclose adjacent kernel memory, remote unauthenticated exploitation is not possible. Additionally, Red Hat Enterprise Linux deployments running on non-s390x architectures do not utilize this hardware-specific subsystem and are entirely unaffected.
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 | 7 | N/A | 7.1 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
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