{"id":"CVE-2026-33945","aliases":["GHSA-q4q8-7f2j-9h9f","GO-2026-4884"],"url":"https://o3.security/vulnerability/CVE-2026-33945","summary":"Abitrary file write through systemd-creds option","details":"### Summary\nIncus instances have an option to provide credentials to systemd in the guest. For containers, this is handled through a shared directory.\nAn attacker can use the name of a systemd credential to escape that directory and overwrite arbitrary files on the host system.\n\nThis can in turn be used to perform local privilege escalation or cause a DoS.\n\n### Details\nAn attacker can set a configuration key named something like `systemd.credential.../../../../../../root/.bashrc` to cause Incus to write outside of the `credentials` directory associated with the container. This makes use of the fact that the Incus syntax for such credentials is `systemd.credential.XYZ` where `XYZ` can itself contain more periods.\n\nWhile it's not possible to read any data this way, it's possible to write to arbitrary files as root, enabling both privilege escalation and denial of service attacks.\n\n### Credit\nThis issue was discovered and reported by the team at [7asecurity](https://7asecurity.com/)","published":"2026-03-26T23:27:45.711Z","modified":"2026-08-12T03:51:32.571560140Z","cvss":{"score":9.9,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"},"epss":{"score":0.00447,"percentile":0.37274,"asOf":"2026-09-01"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/lxc/incus/v6","fixedVersion":"6.23.0"}],"fix":{"url":"https://github.com/lxc/incus/commit/f74199f9983e2ce78f2b78b6d765c6635b229c82","label":"lxc/incus@f74199f"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33945.json"},{"type":"ADVISORY","url":"https://github.com/lxc/incus/security/advisories/GHSA-q4q8-7f2j-9h9f"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33945"},{"type":"WEB","url":"https://github.com/lxc/incus/commit/f74199f9983e2ce78f2b78b6d765c6635b229c82"},{"type":"PACKAGE","url":"https://github.com/lxc/incus"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:32.571560140Z"}}