CVE-2026-23558
📛 CVE Title
grant table v2 race in status page mapping
Description
The adjustments made for XSA-379 as well as those subsequently becoming XSA-387 still left a race window, when a HVM or PVH guest does a grant table version change from v2 to v1 in parallel with mapping the status page(s) via XENMEM_add_to_physmap. Some of the status pages may then be freed while mappings of them would still be inserted into the guest's secondary (P2M) page tables.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- XEN
- CVSS severity
- high
- CVSS score
- 7.8 / 10
- CVSS vector
AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H- Effective score
- 7.8 / 10 HIGH source: CNA overview
- CWE(s)
- —
- Reserved
- 2026-01-14
- Published
- 2026-05-19 12:49 UTC
- Last updated
- 2026-05-20 03:55 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/23xxx/CVE-2026-23558.json
- Linked Threat
- CVE-2026-23558 — CVE-2026-23558
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-05-19 14:16:38 UTC
- NVD last modified
- 2026-05-19 18:55:19 UTC
- NVD CVSS v3.1
- 7.8 / 10 HIGH source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
- NVD CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H- Exploitability subscore
- 1.1 / 10
- Impact subscore
- 6.0 / 10
- EPSS score
- 0.0001 (probability of exploitation in next 30 days)
- EPSS percentile
- 1.36% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD-assigned CWE(s):
CWE-362
(differs from the CNA list above)
NVD / KEV / EPSS data refreshed 2026-05-25 00:45 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-30928 - Assigner
- XEN
- Published
- May 19, 2026, 12:49:54 PM
- Updated
- May 20, 2026, 3:55:35 AM
- EUVD base score (CVSS 3.1)
-
7.8 / 10
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H - EUVD-reported EPSS
- 0.0100
- Aliases
-
GHSA-4qf9-g5cf-cx9j
ENISA description: The adjustments made for XSA-379 as well as those subsequently becoming XSA-387 still left a race window, when a HVM or PVH guest does a grant table version change from v2 to v1 in parallel with mapping the status page(s) via XENMEM_add_to_physmap. Some of the status pages may then be freed while mappings of them would still be inserted into the guest's secondary (P2M) page tables.
EUVD references (1)
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| Xen | Xen |
consult Xen advisory XSA-486 (unknown)
|
— |
Affected products — CPE 2.3 (1) NVD
NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.
cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*
Vendor references (1)
References embedded in the original CVE record by the assigning CNA.
Web references (10)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- https://security.alpinelinux.org/vuln/CVE-2026-23558 rapid7:security.alpinelinux.org
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-30928 rapid7:euvd.enisa.europa.eu
- https://attackerkb.com/topics/CVE-2026-23558 rapid7:attackerkb.com
- http://cwe.mitre.org/data/definitions/362.html rapid7:cwe.mitre.org
- https://www.cve.org/CVERecord?id=CVE-2026-23558 tenable:www.cve.org
- https://www.first.org/epss/ tenable:www.first.org
- https://xenbits.xenproject.org/xsa/advisory-486.html tenable:xenbits.xenproject.org
- http://www.openwall.com/lists/oss-security/2026/04/28/13 tenable:www.openwall.com
- http://xenbits.xen.org/xsa/advisory-486.html tenable:xenbits.xen.org
- https://nvd.nist.gov/vuln/detail/CVE-2026-23558 tenable:nvd.nist.gov
NVD-tagged references (3)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- http://www.openwall.com/lists/oss-security/2026/04/28/13 af854a3a-2127-422b-91ae-364da2661108 Mailing ListMitigationPatchThird Party Advisory
- http://xenbits.xen.org/xsa/advisory-486.html af854a3a-2127-422b-91ae-364da2661108 MitigationPatchVendor Advisory
- https://xenbits.xenproject.org/xsa/advisory-486.html security@xen.org MitigationPatchVendor Advisory
Remediations (20)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:blog.talosintelligence.com
Microsoft has released its monthly security update for May 2026 , which includes 137 vulnerabilities affecting a range of products, including 16 that Microsoft marked as "critical".
2026-05-23 22:15 UTC -
web:blogs.oracle.com
As a follow-up to our recent post, Accelerating Vulnerability Detection and Response, Oracle is announcing the start date and cadence for monthly Critical Security Patch Updates (CSPUs). Beginning May 28, 2026 , Oracle will deliver a Critical Security Patch Update (CSPU) each month.
2026-05-23 22:15 UTC -
web:krebsonsecurity.com
Microsoft expects that exploitation is more likely. May's Patch Tuesday is a welcome respite from April, which saw Microsoft fix a near-record 167 security flaws.
2026-05-23 22:15 UTC -
web:learn.microsoft.com
January 2026 Security Updates This release consists of the following 112 Microsoft CVEs : Tag CVE Base Score CVSS Vector Exploitability FAQs? Workarounds? Mitigations ? Windows Deployment Services CVE - 2026 -0386 SQL Server CVE - 2026 -20803 Windows Hello…
2026-05-23 22:15 UTC -
web:portal.msrc.microsoft.com
The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.
2026-05-23 22:15 UTC -
web:www.crowdstrike.com
Microsoft's February 2026 Patch Tuesday addresses 59 CVEs , featuring six exploited vulnerabilities, three of which were publicly known, and five Critical vulnerabilities.
2026-05-23 22:15 UTC -
web:www.microsoft.com
These Knowledge Base articles accompany all security updates and advisories, and include caveats or known issues with security updates. Additionally, support engineers document common concerns from customers in these KB articles. These Knowledge Base articles are published the Security Update Guide with each release on Patch Tuesday.
2026-05-23 22:15 UTC -
web:www.oracle.com
This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.
2026-05-23 22:15 UTC -
web:www.secpod.com
The second Tuesday of the month has arrived, bringing another significant wave of Microsoft security updates. In February 2026 , Microsoft issued patches for 58 vulnerabilities, including six actively exploited zero-day flaws and five rated Critical. As part of this month's release, Microsoft has also begun rolling out updated Secure Boot certificates ahead of the June 2026 expiration of the ...
2026-05-23 22:15 UTC -
web:zecurit.com
Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .
2026-05-23 22:15 UTC -
web:gbhackers.com
Microsoft has rolled out its August 2025 Patch Tuesday fixes, addressing a total of 107 vulnerabilities across its ecosystem.
2026-05-26 02:57 UTC -
web:krebsonsecurity.com
The reason is that after the Patch Tuesday on October 14, 2025, Microsoft will stop shipping free security updates for Windows 10 computers.
2026-05-26 02:57 UTC -
web:learn.microsoft.com
Learning path Learn how Microsoft supports secure software development as part of a cybersecurity solution - Training Secure software development means integrating security into each phase of your development lifecycle, from requirements analysis to maintenance. Microsoft provides many services that can help you develop more secure code and deploy a more secure application in the cloud. This ...
2026-05-26 02:57 UTC -
web:nvd.nist.gov
An official website of the United States government Here's how you know
2026-05-26 02:57 UTC -
web:petri.com
Windows Aug 13, 2025 August 2025 Patch Tuesday Updates Fix 107 Vulnerabilities Microsoft patches critical flaws and rolls out new Windows features in August 2025 update.
2026-05-26 02:57 UTC -
web:www.absolute.com
Microsoft Patch Tuesday August 2025 delivers 109 fixes, including critical vulnerabilities in MSMQ, NTLM, and graphics components. Stay protected.
2026-05-26 02:57 UTC -
web:www.bleepingcomputer.com
Today is Microsoft's August 2025 Patch Tuesday, which includes security updates for 107 flaws, including one publicly disclosed zero-day vulnerability in Windows Kerberos.
2026-05-26 02:57 UTC -
web:www.crowdstrike.com
Microsoft has released security updates for 107 vulnerabilities, including one publicly disclosed zero-day and 13 critical, in its August 2025 Patch Tuesday rollout.
2026-05-26 02:57 UTC -
web:www.ivanti.com
Microsoft Patch Tuesday serves to keep software systems up to date, and Microsoft tends to have more patch updates in even months than in odd months as a general trend. What Is Patching in Windows? Patches, or fixes, serve to address system vulnerabilities after software has been released.
2026-05-26 02:57 UTC -
web:www.lansweeper.com
Patch Tuesday Microsoft report by Lansweeper. get an overview from all the Microsoft Patch Tuesday 's and fix the vulnerabilities.
2026-05-26 02:57 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-23558.json.
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