CVE-2026-79603CWE-664

CVE-2026-79603

Medium · published September 8, 2026

CVSS v3.1
4.3
EPSS
0%
Percentile
12.1
In the wild
Unconfirmed
What it is

x86 PV guests can free memory pages while still keeping a stale TLB entry

pointing to them. A TLB flush is only issued by Xen (if needed) when the

page is re-used. Since it's possible for the page to be scrubbed ahead of

the TLB flush, there's a window where a PV guest can modify an already

scrubbed page.

The record
Technical detail
CVSS v3.1
4.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00222 · 12.1th percentile
Weakness
CWE-664 · Improper Control of a Resource Through its Lifetime
Published
2026-09-08T17:17Z
References (3)
https://xenbits.xenproject.org/xsa/advisory-511.html · [email protected]http://www.openwall.com/lists/oss-security/2026/09/08/8 · af854a3a-2127-422b-91ae-364da2661108http://xenbits.xen.org/xsa/advisory-511.html · af854a3a-2127-422b-91ae-364da2661108
EPSS history
Timeline
  • 10 SEP 03:18Z
    EPSS moved — → 0%
    epss
  • 08 SEP 12:11Z
    Unconditionally do TLB flushing ahead of page scrubbing
    cvelistv5