Xen Security Advisory 515 v2 (CVE-2026-79608) - x86/AMD: ineffectual Zenbleed workaround

As cited

Copy frozen at 2026-10-13 15:04 UTC (site build).

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Xen Security Advisory 515 v2 (CVE-2026-79608) - x86/AMD: ineffectual Zenbleed workaround

Xen released version 2 of Security Advisory 515 (CVE-2026-79608) to address an ineffectual workaround for Zenbleed on AMD x86 systems. The advisory covers a logic error introduced during reworking of the original XSA-433 mitigation to better integrate with other MSR manipulations.

Why it matters: Administrators running Xen on AMD systems must apply this patch to properly mitigate the Zenbleed vulnerability, as the previous workaround contained an inverted conditional that rendered it ineffective.

Source published

2026-10-13 12:54 UTC

First seen by Cybersecurity Tracker

2026-10-13 13:57 UTC