CVE-2026-79603
MEDIUMCVSS 4.3/10
Last modified
CVE-2026-79603 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. 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.
Description
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.
Metrics
Weakness Enumeration
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Xen | Xen | consult Xen advisory XSA-511 |
References
Timeline
- Published
- Last Modified
- Status
- Awaiting Analysis
Frequently Asked Questions
What is CVE-2026-79603?
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.
How severe is CVE-2026-79603?
CVE-2026-79603 has a CVSS score of 4.3/10 (MEDIUM severity).
How do I fix CVE-2026-79603?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
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Are you affected by CVE-2026-79603?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST