CVE-2026-79608 x86/AMD: ineffectual Zenbleed workaround
A logic error in the Zenbleed mitigation allows attackers to bypass the security workaround, potentially exposing sensitive data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-79608?
CVE-2026-79608 is a critical vulnerability in Xen, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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
Weakness: CWE-670
Which versions are affected by CVE-2026-79608?
How do I fix CVE-2026-79608?
Apply the vendor's patch.
Is CVE-2026-79608 being exploited?
There is no known exploitation of CVE-2026-79608 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-79608, DEBIAN-CVE-2026-79608, GHSA-979q-v7jv-rjpg, UBUNTU-CVE-2026-79608.