CVE-2026-40243Incus OVN TLS verification accepts peer-supplied roots and permits endpoint impersonation
- 2.3LowCVSS base score
- 0.17%Exploitation in 30 daysEPSS · top 93% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
- https://github.com/lxc/incus/security/advisories/GHSA-c839-4qxr-j4x3 (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 26 days later
· 26 days later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | Low2.3 | 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 |
| NVDNVD · Analyzed | 4.0 | Low2.3 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.17% · top 93% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 2.3.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/lxc/incus/v6/cmd/incusdGHSA-c839-4qxr-j4x3 (opens in a new tab)
References
References5
- https://github.com/lxc/incus/security/advisories/GHSA-c839-4qxr-j4x3 (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/lxc/incus/blob/v6.22.0/internal/server/network/ovn/ovn_icnb.go (opens in a new tab)x_refsource_MISC
- https://github.com/lxc/incus/blob/v6.22.0/internal/server/network/ovn/ovn_icsb.go (opens in a new tab)x_refsource_MISC
- https://github.com/lxc/incus/blob/v6.22.0/internal/server/network/ovn/ovn_nb.go (opens in a new tab)x_refsource_MISC
- https://github.com/lxc/incus/blob/v6.22.0/internal/server/network/ovn/ovn_sb.go (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-28211 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-c839-4qxr-j4x3 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-40243)Record last updated .