# CVE-2026-80552: s390/vfio_ccw: Ensure index for read/write regions are within range

CVE-2026-80552 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-80552, released August 27, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-80552
- Priority: High
- CVSS: 8.8 (Important)
- EPSS: 0.0013
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 26, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-80552

## Description

In the Linux kernel, the following vulnerability has been resolved:  s390/vfio_ccw: Ensure index for read/write regions are within range  The introduction of the capability chain rightly clamped the region indexes to the range of the capabilities itself, but neglected to do so for the existing read/write regions which should also be enforced.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.187-1 | [DEBIAN-CVE-2026-80552](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80552.md) | Aug 27, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.105-1 | [DEBIAN-CVE-2026-80552](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80552.md) | Aug 27, 2026 |
| Linux | linux Debian 14 | 7.1.10-1 | [DEBIAN-CVE-2026-80552](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80552.md) | Aug 27, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.107-1~deb12u1 | [DEBIAN-CVE-2026-80552](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80552.md) | Aug 27, 2026 |

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Data as of 2026-11-08T00:53:09Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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