UBUNTU-CVE-2026-40243

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Source
https://ubuntu.com/security/CVE-2026-40243
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40243.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-40243
Upstream
  • CVE-2026-40243
Published
2026-05-06T21:16:00Z
Modified
2026-05-20T16:25:39.260739514Z
Severity
  • 2.3 (Low) CVSS_V4 - CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N CVSS Calculator
  • 4.8 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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.

References

Affected packages

Ubuntu:Pro:24.04:LTS / incus

Package

Name
incus
Purl
pkg:deb/ubuntu/incus?arch=source&distro=esm-apps%2Fnoble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.4-1ubuntu1
0.5.1-1
0.5.1-3
0.6-1
6.*
6.0.0-1
6.0.0-1ubuntu0.1
6.0.0-1ubuntu0.2
6.0.0-1ubuntu0.2+esm1
6.0.0-1ubuntu0.3
6.0.0-1ubuntu0.3+esm1
6.0.0-1ubuntu0.3+esm2
6.0.0-1ubuntu0.3+esm3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "golang-github-lxc-incus-dev",
            "binary_version": "6.0.0-1ubuntu0.3+esm3"
        },
        {
            "binary_name": "incus",
            "binary_version": "6.0.0-1ubuntu0.3+esm3"
        },
        {
            "binary_name": "incus-agent",
            "binary_version": "6.0.0-1ubuntu0.3+esm3"
        },
        {
            "binary_name": "incus-client",
            "binary_version": "6.0.0-1ubuntu0.3+esm3"
        },
        {
            "binary_name": "incus-migrate",
            "binary_version": "6.0.0-1ubuntu0.3+esm3"
        },
        {
            "binary_name": "incus-tools",
            "binary_version": "6.0.0-1ubuntu0.3+esm3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40243.json"

Ubuntu:25.10 / incus

Package

Name
incus
Purl
pkg:deb/ubuntu/incus?arch=source&distro=questing

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

6.*
6.0.3-4
6.0.4-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "golang-github-lxc-incus-dev",
            "binary_version": "6.0.4-2"
        },
        {
            "binary_name": "incus",
            "binary_version": "6.0.4-2"
        },
        {
            "binary_name": "incus-agent",
            "binary_version": "6.0.4-2"
        },
        {
            "binary_name": "incus-base",
            "binary_version": "6.0.4-2"
        },
        {
            "binary_name": "incus-client",
            "binary_version": "6.0.4-2"
        },
        {
            "binary_name": "incus-extra",
            "binary_version": "6.0.4-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40243.json"

Ubuntu:26.04:LTS / incus

Package

Name
incus
Purl
pkg:deb/ubuntu/incus?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

6.*
6.0.4-2
6.0.5-8

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "golang-github-lxc-incus-dev",
            "binary_version": "6.0.5-8"
        },
        {
            "binary_name": "incus",
            "binary_version": "6.0.5-8"
        },
        {
            "binary_name": "incus-agent",
            "binary_version": "6.0.5-8"
        },
        {
            "binary_name": "incus-base",
            "binary_version": "6.0.5-8"
        },
        {
            "binary_name": "incus-client",
            "binary_version": "6.0.5-8"
        },
        {
            "binary_name": "incus-extra",
            "binary_version": "6.0.5-8"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40243.json"