{"id":"CVE-2025-27612","aliases":["GHSA-5w4j-f78p-4wh9"],"url":"https://o3.security/vulnerability/CVE-2025-27612","summary":"Libcontainer is affected by capabilities elevation","details":"### Impact\nIn libcontainer, while creating a tenant container, the tenant builder accepts a list of capabilities to be added in the spec of tenant container. Code can be seen [here](https://github.com/youki-dev/youki/blob/9e63fa4da1672a78ca45100f3059a732784a5174/crates/libcontainer/src/container/tenant_builder.rs#L408) . The logic here adds the given capabilities to all capabilities of main container if present in spec, otherwise simply set provided capabilities as capabilities of the tenant container.\n\nHowever, GHSA-f3fp-gc8g-vw66 was opened on runc mentioning that setting inherited caps in any case for tenant container can lead to elevation of capabilities. For this, they added a fix [here](https://github.com/opencontainers/runc/blob/986451c24e17c8d4be3c454f60b1f7be4af3e8b4/exec.go#L234-L242) where they never set new inherited caps on tenant, and set ambient caps only if original container had inherited caps.\n\nSimilarly crun never sets inherited caps as can be seen [here](https://github.com/containers/crun/blob/3ec6298abd79e144fbf3fa6db90793ff4c0516f9/src/exec.c#L319).\n\n> [!NOTE]\nThis does not affect youki binary itself, as the exec implementation is partially broken and does not pass on the user-provided caps to tenant containers, this is only applicable if you are using libcontainer directly and using the tenant builder.\n\n### Workarounds\n- Do not pass any user-provided capabilities to the tenant builder, in which case no capabilities will be set on tenant.\n- Alternatively you can verify the capabilities of original container and filter the user passed capabilities before setting them on tenant.\n\n### References\n- https://github.com/opencontainers/runc/security/advisories/GHSA-f3fp-gc8g-vw66\n- https://man7.org/linux/man-pages/man7/capabilities.7.html","published":"2025-03-21T14:24:28.756Z","modified":"2026-08-12T03:51:31.447231108Z","cvss":{"score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"},"epss":{"score":0.00174,"percentile":0.06897,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"libcontainer","fixedVersion":"0.5.3"}],"fix":{"url":"https://github.com/youki-dev/youki/commit/747e342d2026fbf3a395db3e2a491ebef00082f1","label":"youki-dev/youki@747e342"},"references":[{"type":"WEB","url":"https://github.com/youki-dev/youki/blob/9e63fa4da1672a78ca45100f3059a732784a5174/crates/libcontainer/src/container/tenant_builder.rs#L408"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/27xxx/CVE-2025-27612.json"},{"type":"ADVISORY","url":"https://github.com/opencontainers/runc/security/advisories/GHSA-f3fp-gc8g-vw66"},{"type":"ADVISORY","url":"https://github.com/youki-dev/youki/security/advisories/GHSA-5w4j-f78p-4wh9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-27612"},{"type":"FIX","url":"https://github.com/youki-dev/youki/commit/747e342d2026fbf3a395db3e2a491ebef00082f1"},{"type":"WEB","url":"https://github.com/containers/crun/blob/3ec6298abd79e144fbf3fa6db90793ff4c0516f9/src/exec.c#L319"},{"type":"WEB","url":"https://github.com/opencontainers/runc/blob/986451c24e17c8d4be3c454f60b1f7be4af3e8b4/exec.go#L234-L242"},{"type":"PACKAGE","url":"https://github.com/youki-dev/youki"},{"type":"WEB","url":"https://man7.org/linux/man-pages/man7/capabilities.7.html"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:31.447231108Z"}}