---
cve: "CVE-2026-89731"
severity: "HIGH"
cvss: 7.1
epss: "21.7%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-09-11 20:20:03"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-15T04:10:56+02:00"
---

# CVE-2026-89731

> 7.1 HIGH

## Beschreibung

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

cxl/ras: Fix cxl_rch_get_aer_info() out-of-bounds AER register read

cxl_rch_get_aer_info() copies the RCH Downstream Port AER capability from
the RCRB MMIO block using a readl() loop bounded by sizeof(struct
aer_capability_regs). This struct is a software layout and its embedded
struct pcie_tlp_log is larger than the on-wire AER capability. As a
result the loop reads past the mapped AER register block.

The over-read also populates the software-only tail fields including
header_log.header_len. An out-of-range header_len passed to
pcie_print_tlp_log() can then loop past the header log buffer and cause
a second out-of-bounds read.

The read was correct when introduced, but struct pcie_tlp_log has since
grown (Header Log and TLP Prefix Log sizes, header_len and flit fields),
so sizeof(struct aer_capability_regs) no longer matches the physical AER
capability.

Bound the read to the physical AER registers, header through the 16 byte
Header Log. Zero the destination first so the software-only fields are
deterministic.

## CVSS-Vektor

```
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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 | Keine | good |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 6.18.51
- Kernel ≥ 7.2.4

## Referenzen

- <https://git.kernel.org/stable/c/29458e62d0829cbc99435f3e44fd560f9bbf1da7>
- <https://git.kernel.org/stable/c/8bd3523df1319edc61cd391e695c84a4618516df>
- <https://git.kernel.org/stable/c/8e3d9dbb25d3ddbe72b4542ec4f7c4e622fe0ced>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-89731) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_