CVE-2026-68451
Description
A flaw was found in the Linux kernel's s390 zcrypt module. The cca_ecc2protkey() function, responsible for handling Common Cryptographic Architecture (CCA) Elliptic Curve Cryptography (ECC) private key requests, does not properly validate the length of the key token. This allows a local attacker to provide a malformed key token, potentially leading to memory corruption and a denial of service.
Statement
This vulnerability is rated as Moderate severity because exploitation requires an authenticated local user on IBM Z (s390x) systems with access to cryptographic device nodes, limiting the blast radius. Systems running on other hardware architectures do not use the s390 zcrypt driver and are not affected by this flaw. Even on vulnerable s390x deployments, triggering the issue requires specific CCA coprocessor hardware interactions to process crafted elliptic-curve tokens.
Mitigation
Mitigation for this issue is either not available or the currently available options don't 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 | 7.8 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | 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 | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/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:H/A:H
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