---
cve: "CVE-2026-53396"
severity: "HIGH"
cvss: 7.1
epss: "27%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-07-19 12:16:50"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-10T10:57:08+02:00"
---

# CVE-2026-53396

> 7.1 HIGH

## Beschreibung

In the Linux kernel, the following vulnerability has been resolved:

nfsd: fix posix_acl leak and ignored error in nfsd4_create_file

nfsd4_create_file() has two bugs in its ACL handling:

The return value of nfsd4_acl_to_attr() is silently discarded.  When
the NFSv4-to-POSIX ACL conversion fails (e.g., -EINVAL for
unsupported ACE types), the file is created without any ACL and the
client receives NFS4_OK.  This violates RFC 7530/8881 which require
the server to reject unsupported attributes on CREATE.

When start_creating() fails after ACL attributes have been populated
in attrs (either via nfsd4_acl_to_attr or via ownership transfer from
open->op_dpacl/op_pacl), the function jumps to out_write which skips
nfsd_attrs_free().  The posix_acl allocations are leaked.  A client
can trigger this repeatedly with OPEN(CREATE), ACL attributes, and an
invalid filename (e.g., longer than NAME_MAX).

Fix both by capturing the nfsd4_acl_to_attr() return value and by
changing the early error paths to jump to out instead of out_write.
Initialize child to ERR_PTR(-EINVAL) so that end_creating() is safe
to call even if start_creating() was never reached.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Gering | warn |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 7.1.3

## Referenzen

- <https://git.kernel.org/stable/c/18cf006a08babec0bbac2a3784f8f28e56e47490>
- <https://git.kernel.org/stable/c/24c975bbdd564d7d0ad90294bfa69729830345de>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-53396) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_