# CVE-2026-53294: mailbox: mailbox-test: don't free the reused channel

CVE-2026-53294 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-53294, released June 27, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-53294
- Priority: High
- CVSS: 7.8 (Moderate)
- EPSS: 0.0018
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 26, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-53294

## Description

In the Linux kernel, the following vulnerability has been resolved:  mailbox: mailbox-test: don't free the reused channel  The RX channel can be aliased to the TX channel if it has a different MMIO. This special case needs to be handled when freeing the channels otherwise a double-free occurs.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.176-1 | [DEBIAN-CVE-2026-53294](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53294.md) | Jun 27, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.94-1 | [DEBIAN-CVE-2026-53294](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53294.md) | Jun 27, 2026 |
| Linux | linux Debian 14 | 7.0.10-1 | [DEBIAN-CVE-2026-53294](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53294.md) | Jun 27, 2026 |

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Data as of 2026-11-08T06:59:42Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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