# CVE-2026-79608: xen: The workaround for XSA-433 (Zenbleed, CVE-2023-20593) was later re-worked to better integrate with other manipulation...

CVE-2026-79608 is fixed in xen on 1 platform, first by DEBIAN-CVE-2026-79608, released October 19, 2026. It is not reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2026-79608
- Priority: Urgent
- CVSS: 9.8 (critical)
- EPSS: 0.0034
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 13, 2026

## Description

The workaround for XSA-433 (Zenbleed, CVE-2023-20593) was later re-worked to better integrate with other manipulations of the same MSR. In this rework an inverted conditional was introduced, resulting in the workaround to not be applied when needed and vice versa.  For more details, see:   http://xenbits.xen.org/xsa/advisory-433.html

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | xen Debian 13.5 (trixie) | 4.20.4+39-gf1e1321c87-0+deb13u1 | [DEBIAN-CVE-2026-79608](https://patchblox.com/security/data/fix/linux/debian-cve-2026-79608.md) | Oct 19, 2026 |
| Linux | xen Debian 14 | 4.20.4+39-gf1e1321c87-1 | [DEBIAN-CVE-2026-79608](https://patchblox.com/security/data/fix/linux/debian-cve-2026-79608.md) | Oct 19, 2026 |
| Linux | xen sles 15.7 | 4.20.4_06-150700.3.49.2 | [SUSE-SU-2026:4942-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4942-1.md) | Nov 7, 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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