# CVE-2026-23554: xen: The Intel EPT paging code uses an optimization to defer flushing of any cached EPT state until the p2m lock is droppe...

CVE-2026-23554 is fixed in xen on 1 platform, first by SUSE-SU-2026:0908-1, released March 17, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-23554
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0013
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 17, 2026

## Description

The Intel EPT paging code uses an optimization to defer flushing of any cached EPT state until the p2m lock is dropped, so that multiple modifications done under the same locked region only issue a single flush.  Freeing of paging structures however is not deferred until the flushing is done, and can result in freed pages transiently being present in cached state. Such stale entries can point to memory ranges not owned by the guest, thus allowing access to unintended memory regions.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | xen Debian 12.15 (bookworm) | 4.17.7-0+deb12u1 | [DEBIAN-CVE-2026-23554](https://patchblox.com/security/data/fix/linux/debian-cve-2026-23554.md) | Mar 23, 2026 |
| Linux | xen Debian 13.5 (trixie) | 4.20.3+127-gc42374a105-0+deb13u1 | [DEBIAN-CVE-2026-23554](https://patchblox.com/security/data/fix/linux/debian-cve-2026-23554.md) | Mar 23, 2026 |
| Linux | xen Debian 14 | 4.20.3+127-gc42374a105-1 | [DEBIAN-CVE-2026-23554](https://patchblox.com/security/data/fix/linux/debian-cve-2026-23554.md) | Mar 23, 2026 |
| Linux | xen opensuse-leap 15.6 | 4.18.5_12-150600.3.40.1 | [SUSE-SU-2026:0908-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0908-1.md) | Mar 17, 2026 |
| Linux | xen sles 15.6 | 4.18.5_12-150600.3.40.1 | [SUSE-SU-2026:0908-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0908-1.md) | Mar 17, 2026 |
| Linux | xen sles 15.7 | 4.20.2_08-150700.3.28.1 | [SUSE-SU-2026:1093-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1093-1.md) | Mar 26, 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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