Auth bypass in Retspen Webvirtcloud
CVE-2026-92761
WebVirtCloud fails to properly validate permission flags in UserInstance grants, allowing view-only users to perform privileged actions. Attackers with read-only grants can power off virtual machines, reset root passwords, install SSH keys, and manage ISO images by exploiting the get_instance gate that only checks grant existence.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (49.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Retspen Webvirtcloud — versions 1b2da68b2800f94674dd96f4a986cde30ac88280
Weakness classification (CWE)
References
- github.com/retspen/webvirtcloud/issues/682 (issue-tracking)
- github.com/retspen/webvirtcloud (product)
- github.com/retspen/webvirtcloud/blob/1b2da68b2800f94674dd96f4a986cde30ac88280/i… (technical-description)
- github.com/retspen/webvirtcloud/blob/1b2da68b2800f94674dd96f4a986cde30ac88280/i… (technical-description)
- github.com/retspen/webvirtcloud/blob/1b2da68b2800f94674dd96f4a986cde30ac88280/i… (technical-description)
- www.vulncheck.com/advisories/webvirtcloud-missing-authorization-on-instance-con… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-92761?
- CVE-2026-92761 is a high-severity vulnerability in Retspen Webvirtcloud, classified under Missing Authorization. CVSS score: 8.8/10. Published 2026-09-16.
- How severe is CVE-2026-92761?
- High severity. CVSS v3 base score is 8.8 out of 10.