VMX: VMentry failure with branch tracing and blocked states
For XSA-308 logic was introduced, as VMX VMEntry checks do not like the exact combination of state which occurs when #DB in intercepted, Single Stepping is active, and blocked by STI/MovSS is active, despite this being a legitimate state to be in. The resulting VMEntry failure is fatal to the guest. Sadly there is another special sub-case of the above, with branch tracing enabled. In that case the prior adjustment would still cause a VMentry failure, as before fatal to the guest.
CVE-2026-79611
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-79611
Xen
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "Xen",
"product": "Xen",
"versions": [
{
"status": "unknown",
"version": "consult Xen advisory XSA-518"
}
],
"defaultStatus": "unknown"
}
]- Related CVEs
- CVE-2026-79611
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #42423 · Revision 1
- Added to Heist Feed
- Publisher date