# CVE-2026-80551: s390/vfio_ccw: Ensure first IDAW remains constant

CVE-2026-80551 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-80551, released August 27, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-80551
- Priority: High
- CVSS: 9.3 (Moderate)
- EPSS: 0.0014
- 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-2026-80551

## Description

In the Linux kernel, the following vulnerability has been resolved:  s390/vfio_ccw: Ensure first IDAW remains constant  The first IDAW in a list does not need to be on a 2K/4K boundary like all others, and so is read separately to accurately calculate the size of the buffer needed to read the full IDAL.  Verify that the address found in the first IDAW is unchanged between reads, to ensure a consistent set of IDAWs being worked with.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 13.5 (trixie) | 6.12.105-1 | [DEBIAN-CVE-2026-80551](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80551.md) | Aug 27, 2026 |
| Linux | linux Debian 14 | 7.1.10-1 | [DEBIAN-CVE-2026-80551](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80551.md) | Aug 27, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.107-1~deb12u1 | [DEBIAN-CVE-2026-80551](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80551.md) | Aug 27, 2026 |

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Data as of 2026-11-09T01:18:40Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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