---
cve: "CVE-2026-90038"
severity: "CRITICAL"
cvss: 9.8
epss: "77.6%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-09-16 11:17:17"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-19T06:40:27+02:00"
---

# CVE-2026-90038

> 9.8 CRITICAL

## Beschreibung

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

NFSD: Prevent client use-after-free during export state revocation

nfsd4_revoke_export_states() has the same use-after-free as
nfsd4_revoke_states(): it drops nn->client_lock across
revoke_one_stid() and the following read of clp->cl_minorversion, but
the stateid reference it holds does not pin the client.  A teardown
racing the dropped lock can free the client while revoke_one_stid()
still dereferences it.

exportfs -u drives this path through NFSD_CMD_UNLOCK_EXPORT, so an
administrator removing an export can race a client expiry.

Skip a client that is already expiring and otherwise pin it with
cl_rpc_users under client_lock before dropping the lock, matching
nfsd4_revoke_states().

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- Kernel ≥ 7.2.5

## Referenzen

- <https://git.kernel.org/stable/c/c05ae58fe06ce2ac34312f649e71c3596bdde358>
- <https://git.kernel.org/stable/c/2108de53568a64936a0da3e04d85c35df98d3fb6>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-90038) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_