CVE-2026-89672
Description
A flaw was found in the Linux kernel's Network File System (NFS) server daemon (nfsd). When processing NFSACL version 2 SETACL requests, the system could unintentionally remove a directory's default Access Control List (ACL) or both access and default ACLs. This occurs because the set_posix_acl() function is called unconditionally, even if the request mask indicates that no ACLs should be set, leading to an unintended removal operation. This could allow an attacker to modify file system permissions without authorization.
Statement
This vulnerability is rated as Moderate impact for Red Hat Enterprise Linux because exploitation requires an active NFS server configured to support legacy NFS version 2 exports with POSIX ACLs enabled. On standard Red Hat installations, the NFS server daemon is not enabled by default, and modern releases disable NFS version 2 by default. Consequently, exposure is confined to environments actively serving legacy NFS shares where clients have permission to modify directory attributes.
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 | 9.1 |
| Attack Vector | Local | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | N/A | None |
| 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 | None |
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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
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