---
cve: "CVE-2026-89669"
severity: "CRITICAL"
cvss: 9.8
epss: "58.7%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-09-11 20:19:53"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-17T04:58:07+02:00"
---

# CVE-2026-89669

> 9.8 CRITICAL

## Beschreibung

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

nfsd: initialize copy-notify stateid before publishing it

nfsd4_copy_notify() finished initializing the cpntf state after
nfs4_alloc_init_cpntf_state() had already linked it into the
s2s_cp_stateids IDR and the parent's sc_cp_list, with cs_count == 1 (the
membership reference) and none held for the caller. A racing
OFFLOAD_CANCEL (crafted cl_id == nn->s2s_cp_cl_id plus the guessable
so_id) could reach manage_cpntf_state() and free the entry, turning the
caller's subsequent cpn_cnr_stateid read and cp_p_stateid/cp_p_clid
writes into use-after-free. The owning clientid was also only recorded
after publication, so it could not gate an ownership check in that window.

Record cp_p_stateid and cp_p_clid inside nfs4_alloc_init_cpntf_state()
before nfs4_init_cp_state() publishes the entry, and return it with an
extra reference. The caller reads the stateid under that reference and
drops it with nfs4_put_cpntf_state(); on a late error the laundromat
reaps the entry.

## 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 ≥ 5.10.270
- Kernel ≥ 5.15.221
- Kernel ≥ 6.1.188
- Kernel ≥ 6.6.157
- Kernel ≥ 6.12.109
- Kernel ≥ 6.18.50
- Kernel ≥ 7.2.4

## Referenzen

- <https://git.kernel.org/stable/c/129643893b79f8a3c6b72045f933fbab5ee424ca>
- <https://git.kernel.org/stable/c/4415a692346a39fdb647cbd717eda510159aaf55>
- <https://git.kernel.org/stable/c/4cdef96892f4fa6e70c405b6e8f2fd6972f3b64b>
- <https://git.kernel.org/stable/c/863b6e995665472f2af5be2436a874ab6a9e5ac6>
- <https://git.kernel.org/stable/c/9caad13b7cfe9ccb90cc405ac77335800e086595>
- <https://git.kernel.org/stable/c/a4d7fedcaaf33e60a01e53eafca9041ef966212f>
- <https://git.kernel.org/stable/c/d18d36395d973ef7372c8e6724970585f75b5c0b>
- <https://git.kernel.org/stable/c/e08a3dcaca0505f861e344a387f37f94d95dbdc2>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-89669) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_