CVE-2026-40243: lxc incus · Improper Certificate Validation
Affects lxc incusSource CVE Database V5
Not known to be exploited · CVSS 2.3 Low : upgrade to 7.0.0 when convenient.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0
CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 6 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade incus and lxc/incus to 7.0.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| lxcincus | Affected
| Fixed in
|
GitHublxc/incuspkg:github/lxc/incusOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
This vulnerability is fixed in Incus version 7.0.0. Users should upgrade to version 7.0.0 or later to resolve this issue. Until upgraded, deployments should consider restricting network access to the OVN database endpoint to trusted hosts to reduce risk.
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.
References
- github.com/lxc/incus/security/advisories/GHSA-c839-4qxr-j4x3 (opens in a new tab)
- github.com/lxc/incus/blob/v6.22.0/internal/server/network/ovn/ovn_icnb.go (opens in a new tab)
- github.com/lxc/incus/blob/v6.22.0/internal/server/network/ovn/ovn_icsb.go (opens in a new tab)
- github.com/lxc/incus/blob/v6.22.0/internal/server/network/ovn/ovn_nb.go (opens in a new tab)
- github.com/lxc/incus/blob/v6.22.0/internal/server/network/ovn/ovn_sb.go (opens in a new tab)