CVE-2026-40243: Incusd · Incus has an OVN TLS Verification that Accepts Peer-Supplied Roots
Affects github.com/lxc/incus/v6/cmd/incusdSource GCVE Database
Not known to be exploited · CVSS 2.3 Low : upgrade to 7.0.0 when convenient.
Data as of 27 Oct 2026, 03:27 UTC
- 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
Weaponised: 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 26 Oct 2026.
What to do
Upgrade github.com/lxc/incus/v6/cmd/incusd to 7.0.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Gogithub.com/lxc/incus/v6/cmd/incusd | 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
A patch is available and should be applied by upgrading Incus to version 7.0.0 or later. This update corrects the TLS verification logic to properly anchor trust in the configured CA certificate, preventing acceptance of peer-supplied roots. No additional mitigation steps are necessary once the patch is applied.
Description
A broken TLS validation logic in the OVN database connection within Incus allows an attacker who can intercept the OVN endpoint to impersonate the OVN database by presenting a rogue self-signed certificate. The vulnerability arises because the custom TLS verifier accepts peer-supplied root certificates instead of anchoring trust in the configured CA certificate, undermining the intended authentication model. This affects authenticated connections from Incus to OVN northbound and southbound databases, which are critical for logical network configuration and control-plane coordination. The flaw reduces CA-anchored authentication to endpoint impersonation by an attacker with network access, but exploitation is difficult due to typical deployment architectures. A fix is available in Incus version 7.0.0.
References
- github.com/lxc/incus/security/advisories/GHSA-c839-4qxr-j4x3 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-40243 (opens in a new tab)
- github.com/lxc/incus (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)