---
cve: "CVE-2026-80931"
severity: "HIGH"
cvss: 7.8
epss: "18.5%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-09-11 20:18:56"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-16T09:35:09+02:00"
---

# CVE-2026-80931

> 7.8 HIGH

## Beschreibung

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

w1: ds28e17: reject an oversize length on an I2C block read

w1_f19_i2c_master_transfer() is the master_xfer for the DS28E17 1-Wire
to I2C bridge. On an I2C_M_RECV_LEN read, it takes the length from the
device. The downstream slave puts a length byte in buf[0]. The driver
then reads that many bytes into buf[1] with w1_f19_i2c_read().

buf[0] is controlled by the device and can be 0 to 255.
w1_f19_i2c_read() only rejects a zero count. The caller buffer is
I2C_SMBUS_BLOCK_MAX + 2, so 34 bytes. A length above 32 makes the read
run past it, up to about 222 bytes out of bounds.

The SMBus core does check buf[0] against I2C_SMBUS_BLOCK_MAX. That
check runs after master_xfer returns. By then the write is already
done. i2c-algo-bit rejects an oversize length before it copies, and
returns -EPROTO.

Reject a length above I2C_SMBUS_BLOCK_MAX at both RECV_LEN sites, the
same way i2c-algo-bit does.

## CVSS-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| 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/0f6496b34cc2919420f303b2aabdd9f71e084b56>
- <https://git.kernel.org/stable/c/169ae5e65e5aaf213b6a578f6478a9fd2e523606>
- <https://git.kernel.org/stable/c/1d08877fc37e90945df38d255715bd1d6c052d46>
- <https://git.kernel.org/stable/c/6df05f630c84a109736642362e452089886f9974>
- <https://git.kernel.org/stable/c/ae0c79a8527044e54d81fd5a3b49ce6177633758>
- <https://git.kernel.org/stable/c/b30c021c6073559ea6851b522d8a17a524a27b4a>
- <https://git.kernel.org/stable/c/bf76d61e118b7044600a65775a3bf8adc2c6823d>
- <https://git.kernel.org/stable/c/cb55c5da9828f77db2a2701316949d4de1e9b773>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-80931) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_
