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CVE-2026-62440

CRITICAL 9.1

Published 2026-08-21 · Last modified 2026-08-25

Improper Access Control vulnerability in Apache CloudStack's Kubernetes Service (CKS) plugin, allowing cross-tenant manipulation of the Kubernetes cluster while adding and removing nodes. This issue affects Apache CloudStack: from 4.21.0.0 through 4.22.1.0. Users are recommended to upgrade to version 4.22.1.1 or later, which fixes the issue.

ELEVATED IMPACT

Severe if exploited (CVSS 9.1), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.3%chance of exploitation in 30 days · 22nd percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

9.1CVSS 3.1 · CRITICAL

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityNone

What an attacker needs

  • Access: Reachable over the network — no local access needed
  • Privileges: No account or privileges required
  • User interaction: No user interaction needed
  • Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-62440/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-62440/poc.json

Affected

Vendors Apache Software Foundation Apache

Products Apache Cloudstack Cloudstack

Weakness (CWE)

  • CWE-284: Improper Access Control

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Known Affected Software Configurations

VendorProductVersion range
ApacheCloudstack≥ 4.21.0.0 and < 4.22.1.1

All CVSS metrics

  • CRITICAL 9.1 v3.1 · ADP Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
  • CRITICAL 9.1 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References

Advisories

Sources: NVD · CVE.org · EPSS