# CVE-2026-89506

## Summary

- **CVE ID:** CVE-2026-89506
- **Severity:** UNKNOWN
- **CVSS Score:** 1.51
- **CWE:** N/A
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 16, 2026

## Description

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

RDMA/uverbs: Add UVERBS_ATTR_UHW to UVERBS_METHOD_REG_MR

The original commit missed that three drivers (mthca, irdma, siw) have UHW
data associated with reg_mr that cannot be passed through the ioctl. They
also assume that the udata cannot be NULL, so failing to pass a valid
udata can trigger a NULL udata crash in those drivers.

This never happens in real systems since in rdma-core ibv_cmd_reg_mr_ex()
does not accept a udata and those three drivers don't use it, however a
malicious userspace could trigger it.

## Affected Products

- Linux — Linux (5b2e45049dc06a876bc6b138218ddeb0814502ef)
- Linux — Linux (6.17)
- Linux — Linux (0)
- Linux — Linux (6.18.50)
- Linux — Linux (7.2.4)
- Linux — Linux (7.3-rc1)

## References

- [CNA](https://git.kernel.org/stable/c/71d5c41ac583df09a7c32199bef7d42de7267d07)
- [CNA](https://git.kernel.org/stable/c/9e71d0f4944ba5641e01db29b3256c963656d671)
- [CNA](https://git.kernel.org/stable/c/011199f46f44a9fd93a9e5ab5d7fd1328d80e9bf)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.17%
- **EPSS Percentile:** 6.3

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._