CVE-2026-42488 x86: mismatched mapcache metadata
A flaw in Xen's shadow paging allows memory corruption, potentially enabling code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42488?
CVE-2026-42488 is a high-severity memory corruption vulnerability in Xen, published on 18 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Some shadow paging errors paths will switch the page-tables without updating the currently running vCPU reference. This causes a mismatch between the loaded page-tables and the mapcache metadata which can lead to corruption of the mapcache.
Weakness: CWE-119
Which versions are affected by CVE-2026-42488?
How do I fix CVE-2026-42488?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-42488 being exploited?
There is no known exploitation of CVE-2026-42488 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-42488, DEBIAN-CVE-2026-42488, GHSA-7jcv-rhv5-mq52, UBUNTU-CVE-2026-42488.