CVE-2026-40243 Details
Description
Incus is a system container and virtual machine manager. In versions before 7.0.0, broken TLS validation logic in the OVN database connection logic can allow connections to an attacker's OVN database. The OVN client implementations disable Go standard TLS server verification and replace it with custom peer-certificate verification logic. That replacement verifier does not anchor trust in the configured CA certificate. Instead, it constructs the verification root set from certificates supplied by the peer during the handshake, so the configured CA is parsed but not used as the trust anchor for the final verification decision. In OVN-enabled deployments that use these SSL database connection paths, an attacker able to impersonate or intercept the OVN endpoint on the management network can present a rogue self-signed certificate chain, and Incus will accept this certificate as valid. This issue defeats the intended CA-based trust model for OVN database connections and permits endpoint impersonation by an active attacker in a suitable network position. This issue is fixed in version 7.0.0.
A vulnerability exists in Incus, a system container and virtual machine manager, in versions prior to 7.0.0. The issue arises from flawed TLS validation in the Open Virtual Network (OVN) database connection logic, which can enable connections to an attacker's OVN database. This vulnerability is present because the OVN client implementations disable standard TLS server verification and replace it with custom peer-certificate verification that does not properly anchor trust in the configured CA certificate. Instead, it relies on certificates supplied by the peer during the handshake, allowing an attacker to present a rogue self-signed certificate chain that is accepted as valid. This flaw undermines the intended CA-based trust model for OVN database connections, particularly in clustered deployments where it can lead to endpoint impersonation by an active attacker on the management network.
Users can upgrade to Incus version 7.0.0 or later, where this vulnerability is fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 7, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-295 | Improper Certificate Validation | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linuxcontainers incus | < 7.0.0 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 8, 2026 | Initial Analysis | [email protected] |
| May 7, 2026 | CVE Modified | CISA-ADP |
| May 6, 2026 | New CVE Received | [email protected] |