{"id":"CVE-2025-62161","aliases":["EUVD-2025-37939","GHSA-4g74-7cff-xcv8"],"status":"published","title":"youki container escape via \"masked path\" abuse due to mount race conditions","description":"Youki is a container runtime written in Rust. In versions 0.5.6 and below, the initial validation of the source /dev/null is insufficient, allowing container escape when youki utilizes bind mounting the container's /dev/null as a file mask. This issue is fixed in version 0.5.7.","severity":{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00259,"percentile":0.17744,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-363","CWE-61"],"published":"2025-11-05T18:44:18Z","modified":"2026-10-28T02:31:10Z","fixes":[{"ecosystem":"crates.io","package":"youki","fixed_in":["0.5.7"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"youki","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.5.7"}]}]},{"source":"osv","ecosystem":"crates.io","package":"youki","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.5.7"}]}]}],"products":[{"vendor":"youki-dev","product":"youki"}],"references":[{"url":"https://github.com/youki-dev/youki/security/advisories/GHSA-4g74-7cff-xcv8","tags":["x_refsource_CONFIRM","x_refsource_MISC","Vendor Advisory","advisory","web"]},{"url":"https://github.com/youki-dev/youki/commit/5886c91073b9be748bd8d5aed49c4a820548030a","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-62161","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-4g74-7cff-xcv8"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/62xxx/CVE-2025-62161.json","tags":["advisory"]},{"url":"https://github.com/youki-dev/youki","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2025-62161","title":"youki container escape via \"masked path\" abuse due to mount race conditions","description":"Youki is a container runtime written in Rust. In versions 0.5.6 and below, the initial validation of the source /dev/null is insufficient, allowing container escape when youki utilizes bind mounting the container's /dev/null as a file mask. This issue is fixed in version 0.5.7.","status":"published","published":"2025-11-05T23:09:09.014Z","modified":"2025-11-06T21:20:19.865Z","cvss":[{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"high","assessor":"cna"}],"cwes":["CWE-363","CWE-61"],"updated_at":"2026-11-02T14:32:54.87586Z"}],"euvd":[{"id":"EUVD-2025-37939","description":"Youki is a container runtime written in Rust. In versions 0.5.6 and below, the initial validation of the source /dev/null is insufficient, allowing container escape when youki utilizes bind mounting the container's /dev/null as a file mask. This issue is fixed in version 0.5.7.","status":"published","published":"2025-11-05T23:09:09Z","modified":"2025-11-06T21:20:19Z","cvss":[{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"high"}],"updated_at":"2026-11-02T19:49:19.806495Z"}],"ghsa":[{"id":"GHSA-4g74-7cff-xcv8","title":"youki container escape via \"masked path\" abuse due to mount race conditions","description":"### Impact ###\n\nyouki utilizes bind mounting the container's `/dev/null` as a file mask. When performing this operation, the initial validation of the source `/dev/null` was insufficient. Specifically, we initially failed to verify whether `/dev/null` was genuinely present. However, we did perform validation to ensure that the `/dev/null` path existed within the container, including checking for symbolic links. Additionally, there was a vulnerability in the timing between validation and the actual mount operation.\n\nAs a result, by replacing `/dev/null` with a symbolic link, we can bind-mount arbitrary files from the host system.\n\nThis is a different project, but the core logic is similar to the CVE in runc. Issues were identified in runc, and verification was also conducted in youki to confirm the problems.\nhttps://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2\n\n### Credits\n\nThanks to Lei Wang (@ssst0n3 from Huawei) for finding and reporting the original runc's vulnerability (Attack 1), and Li Fubang (@lifubang from acmcoder.com, CIIC) for discovering another attack vector in runc (Attack 2) based on @ssst0n3's initial findings.\n\nAlso, @cyphar helped youki in finding the problem.","status":"published","published":"2025-11-05T18:44:18Z","modified":"2025-11-15T02:25:02Z","cvss":[{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"high"},{"version":"3.1","score":10,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-61","CWE-363"],"updated_at":"2026-11-02T14:39:08.983925Z"}],"nvd":[{"id":"CVE-2025-62161","description":"Youki is a container runtime written in Rust. In versions 0.5.6 and below, the initial validation of the source /dev/null is insufficient, allowing container escape when youki utilizes bind mounting the container's /dev/null as a file mask. This issue is fixed in version 0.5.7.","status":"published","published":"2025-11-06T00:15:36.76Z","modified":"2026-10-19T13:10:00.11Z","cvss":[{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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","level":"high","assessor":"secondary"},{"version":"3.1","score":10,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"primary"}],"cwes":["CWE-61","CWE-363"],"updated_at":"2026-11-02T14:11:42.142547Z"}],"osv":[{"id":"CVE-2025-62161","title":"youki container escape via \"masked path\" abuse due to mount race conditions","description":"Youki is a container runtime written in Rust. In versions 0.5.6 and below, the initial validation of the source /dev/null is insufficient, allowing container escape when youki utilizes bind mounting the container's /dev/null as a file mask. This issue is fixed in version 0.5.7.","status":"published","published":"2025-11-05T23:09:09.014Z","modified":"2026-10-28T02:31:10.112611322Z","cvss":[{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"high"}],"cwes":["CWE-363","CWE-61"],"updated_at":"2026-11-02T15:44:51.516975Z"},{"id":"GHSA-4g74-7cff-xcv8","title":"youki container escape via \"masked path\" abuse due to mount race conditions","description":"### Impact ###\n\nyouki utilizes bind mounting the container's `/dev/null` as a file mask. When performing this operation, the initial validation of the source `/dev/null` was insufficient. Specifically, we initially failed to verify whether `/dev/null` was genuinely present. However, we did perform validation to ensure that the `/dev/null` path existed within the container, including checking for symbolic links. Additionally, there was a vulnerability in the timing between validation and the actual mount operation.\n\nAs a result, by replacing `/dev/null` with a symbolic link, we can bind-mount arbitrary files from the host system.\n\nThis is a different project, but the core logic is similar to the CVE in runc. Issues were identified in runc, and verification was also conducted in youki to confirm the problems.\nhttps://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2\n\n### Credits\n\nThanks to Lei Wang (@ssst0n3 from Huawei) for finding and reporting the original runc's vulnerability (Attack 1), and Li Fubang (@lifubang from acmcoder.com, CIIC) for discovering another attack vector in runc (Attack 2) based on @ssst0n3's initial findings.\n\nAlso, @cyphar helped youki in finding the problem.","status":"published","published":"2025-11-05T18:44:18Z","modified":"2025-11-15T02:25:02Z","cvss":[{"version":"3.1","score":10,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical"},{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","level":"high"}],"cwes":["CWE-363","CWE-61"],"updated_at":"2026-11-02T15:46:36.782754Z"}]}}