CVE-2026-25199
📛 CVE Title
Apache CloudStack: Proxmox Extension Allows Unauthorized Cross-Tenant Instance Access
Description
Instances deployed via the Proxmox extension allow unauthorized access to instances belonging to other tenants. This issue affects Apache CloudStack: from 4.21.0.0 through 4.22.0.0. The Proxmox extension for CloudStack improperly uses a user-editable instance setting, proxmox_vmid, to associate CloudStack instances with Proxmox virtual machines. Because this value is not restricted or validated against tenant ownership and Proxmox VM IDs are predictable, a non-privileged attacker can modify the setting to reference a VM belonging to another account. This allows unauthorized cross-tenant access and enables full control over the targeted VM, including starting, stopping, and destroying the virtual machine. Users are recommended to upgrade to version 4.22.0.1, which fixes this issue. As a workaround for the existing installations, editing of the proxmox_vmid instance detail by users can be prevented by adding this detail name to the global configuration parameter - user.vm.denied.details.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- apache
- CVSS severity
- critical
- CVSS score
- 9.1 / 10
- CVSS vector
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N- Effective score
- 9.1 / 10 CRITICAL source: CNA overview
- CWE(s)
-
CWE-200 - Reserved
- 2026-01-30
- Published
- 2026-05-08 14:22 UTC
- Last updated
- 2026-05-09 08:43 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/25xxx/CVE-2026-25199.json
- Linked Threat
- CVE-2026-25199 — CVE-2026-25199
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
- 2026-05-08 13:16:36 UTC
- NVD last modified
- 2026-05-09 07:16:09 UTC
- NVD CVSS v3.1
- 9.1 / 10 CRITICAL source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 5.2 / 10
- EPSS score
- 0.0004 (probability of exploitation in next 30 days)
- EPSS percentile
- 10.78% vs all CVEs — higher = more likely to be exploited, as of 2026-05-25
NVD / KEV / EPSS data refreshed 2026-05-25 18:39 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-2026-28550 - Assigner
- apache
- Published
- May 8, 2026, 12:22:56 PM
- Updated
- May 9, 2026, 6:43:07 AM
- EUVD base score (CVSS 3.1)
-
9.1 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - EUVD-reported EPSS
- 0.0400
- Vendors
- Apache Software Foundation
- Products
-
Apache CloudStack (4.21.0 ≤4.22.0)
ENISA description: Instances deployed via the Proxmox extension allow unauthorized access to instances belonging to other tenants. This issue affects Apache CloudStack: from 4.21.0.0 through 4.22.0.0. The Proxmox extension for CloudStack improperly uses a user-editable instance setting, proxmox_vmid, to associate CloudStack instances with Proxmox virtual machines. Because this value is not restricted or validated against tenant ownership and Proxmox VM IDs are predictable, a non-privileged attacker can modify the setting to reference a VM belonging to another account. This allows unauthorized cross-tenant access and enables full control over the targeted VM, including starting, stopping, and destroying the virtual machine. Users are recommended to upgrade to version 4.22.0.1, which fixes this issue. As a workaround for the existing installations, editing of the proxmox_vmid instance detail by users can be prevented by adding this detail name to the global configuration parameter - user.vm.denied.details.
EUVD references (1)
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| Apache Software Foundation | Apache CloudStack |
4.21.0 (affected)
|
— |
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:a:apache:cloudstack:*:*:*:*:*:*:*:*
Vendor references (1)
References embedded in the original CVE record by the assigning CNA.
- https://lists.apache.org/thread/n8mt5b7wkpysstb8w7rr9f02kc5cq2xm vendor-advisory
MITRE references (1) cveawg.mitre.org
Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.
- https://lists.apache.org/thread/n8mt5b7wkpysstb8w7rr9f02kc5cq2xm vendor-advisory
Web references (4)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- http://www.openwall.com/lists/oss-security/2026/05/09/7 tenable:www.openwall.com
- https://nvd.nist.gov/vuln/detail/CVE-2026-25199 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-25199 tenable:www.cve.org
- https://www.first.org/epss/ tenable:www.first.org
NVD-tagged references (2)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://lists.apache.org/thread/n8mt5b7wkpysstb8w7rr9f02kc5cq2xm security@apache.org Mailing ListVendor Advisory
- http://www.openwall.com/lists/oss-security/2026/05/09/7 af854a3a-2127-422b-91ae-364da2661108
Remediations (20)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:blog.qualys.com
With Qualys Policy Audit's out-of-the-box mitigation or Compensatory Controls, which reduce the risk of a vulnerability being exploited because the remediation ( fix / patch ) cannot be done immediately, these security controls are not recommended by any industry standards, such as CIS and DISA-STIG.
2026-05-23 21:06 UTC -
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 21:06 UTC -
web:cyberscoop.com
Threats Microsoft addresses 137 vulnerabilities in May's Patch Tuesday, including 13 rated critical The high volume of vulnerabilities reflects a growing trend researchers have been anticipating as artificial intelligence models are deployed to find previously uncovered defects in code.
2026-05-23 21:06 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 21:06 UTC -
web:nvd.nist.gov
Secure .gov websites use HTTPS A lock () or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.
2026-05-23 21:06 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 21:06 UTC -
web:support.microsoft.com
This cumulative update for Windows 11, version 25H2 and 24H2 (KB5083769), includes the latest security fixes and improvements, along with non-security updates from last month's optional preview release. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained ...
2026-05-23 21:06 UTC -
web:www.bleepingcomputer.com
Today is Microsoft's May 2026 Patch Tuesday, with security updates for 120 flaws and no zero-days disclosed this month.
2026-05-23 21:06 UTC -
web:www.windowslatest.com
Windows 11 April 2026 update adds Narrator Copilot support, faster Settings, File Explorer fixes, and key security improvements.
2026-05-23 21:06 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 21:06 UTC -
web:community.ui.com
Published: May 21, 2026 Updated: May 22, 2026 Version: 1.1 Revision: 1.1 Summary 1 of 5 A malicious actor with access to the network and high privileges could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection. Affected Products: UniFi OS Server (Version 5.0.6 and earlier) Mitigation : Update your UniFi OS Server to Version 5.0.8 or later ...
2026-05-26 02:47 UTC -
web:docs.openclaw.ai
Migration checklist Use this checklist when you already know your old BlueBubbles config and want the shortest safe path: Verify imsg directly on the Mac that runs Messages.app (imsg chats, imsg history, imsg send, and imsg rpc --help). Copy behavior keys from channels.bluebubbles to channels.imessage: dmPolicy, allowFrom, groupPolicy, groupAllowFrom, groups, includeAttachments ...
2026-05-26 02:47 UTC -
web:en-forum.guildwars2.com
03/31/2026—March 31 Release Notes Note to users of third-party programs: The game may not launch or work properly after we release a new build if you use a third-party program, due to possible incompatibilities. ArenaNet cannot offer support if a third-party modification breaks, interferes with, ...
2026-05-26 02:47 UTC -
web:msrc.microsoft.com
Security Update Guide - Microsoft Security Response Center
2026-05-26 02:47 UTC -
web:translate.google.com
Google's service, offered free of charge, instantly translates words, phrases, and web pages between English and over 100 other languages.
2026-05-26 02:47 UTC -
web:www.forbes.com
Updated May 17: This article, originally published May 16, has been updated to include further details on the emergency mitigation process recommended after the CVE - 2026 -42897 Microsoft Exchange ...
2026-05-26 02:47 UTC -
web:www.lci.ca.gov
Office of Planning and Research
2026-05-26 02:47 UTC -
web:www.princegeorgescountymd.gov
Learn more about the Permanent Rent Stabilization and Protection Act of 2024 which sets clear limits on how much rent can increase annually for for most rental units (regulated units).
2026-05-26 02:47 UTC -
web:www.virustotal.com
VirusTotal is a platform for scanning files and URLs for viruses, malware, and other threats using multiple antivirus engines.
2026-05-26 02:47 UTC -
web:www.youtube.com
Catch A Monster Roblox Patch 0.32 is live, and this update adds a lot: Draco Spike Evo, the new Mutation Extractor, Jokaire from the Mobius Circus slot machi...
2026-05-26 02:47 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-25199.json.
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