# CVE-2026-90192: mailbox: qcom-cpucp: handle NULL data in send_data callback

CVE-2026-90192 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-90192, released September 23, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-90192
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0021
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 17, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-90192

## Description

In the Linux kernel, the following vulnerability has been resolved:  mailbox: qcom-cpucp: handle NULL data in send_data callback  mailbox_clear_channel() calls mbox_send_message() with NULL data to notify the remote side that the RX channel has been cleared. qcom_cpucp_mbox_send_data() blindly dereferenced the data pointer, causing a NULL pointer dereference kernel panic when invoked from this path under PREEMPT_RT.  Add an explicit NULL check and return early without writing to the TX register, which is the correct behaviour for a channel-clear notification.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 13.5 (trixie) | 6.12.111-1 | [DEBIAN-CVE-2026-90192](https://patchblox.com/security/data/fix/linux/debian-cve-2026-90192.md) | Sep 23, 2026 |
| Linux | linux Debian 14 | 7.2.6-1 | [DEBIAN-CVE-2026-90192](https://patchblox.com/security/data/fix/linux/debian-cve-2026-90192.md) | Sep 23, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.111-1~deb12u1 | [DEBIAN-CVE-2026-90192](https://patchblox.com/security/data/fix/linux/debian-cve-2026-90192.md) | Sep 23, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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