---
cve: "CVE-2026-74573"
severity: "CRITICAL"
cvss: 9.3
epss: "13%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-08-15 13:18:02"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-08-31T12:51:02+02:00"
---

# CVE-2026-74573

> 9.3 CRITICAL

## Beschreibung

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

iommu/arm-smmu-v3-iommufd: Require exactly one Stream ID for a vDEVICE

arm_vsmmu_vsid_to_sid() maps a guest's vSID to a single physical Stream ID
taken from master->streams[0], assuming a device has exactly one stream. A
device with several streams gets only its first one mapped, so a guest vSID
invalidation cannot reach the others' ATC and IOTLB entries; a device with
none makes master->streams a ZERO_SIZE_PTR, read out of bounds.

Add an arm_vsmmu_vdevice_init() op to reject the vDEVICE with -EOPNOTSUPP
when master->num_streams is not one, rather than mapping it silently.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- Kernel ≥ 6.18.44
- Kernel ≥ 7.1.8

## Referenzen

- <https://git.kernel.org/stable/c/3808bab5d95ae79e333e11f6a73d178e084c645d>
- <https://git.kernel.org/stable/c/0acbc621341aca4eb94d9c2f43e1ab273ff088f0>
- <https://git.kernel.org/stable/c/c3b8ee84a965058b41275069d4696f37a8b14bf6>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-74573) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_