{"id":"CVE-2025-31133","aliases":["GHSA-9493-h29p-rfm2","GO-2025-4096"],"url":"https://o3.security/vulnerability/CVE-2025-31133","summary":"runc container escape via \"masked path\" abuse due to mount race conditions","details":"runc is a CLI tool for spawning and running containers according to the OCI specification. In versions 1.2.7 and below, 1.3.0-rc.1 through 1.3.1, 1.4.0-rc.1 and 1.4.0-rc.2 files, runc would not perform sufficient verification that the source of the bind-mount (i.e., the container's /dev/null) was actually a real /dev/null inode when using the container's /dev/null to mask. This exposes two methods of attack:  an arbitrary mount gadget, leading to host information disclosure, host denial of service, container escape, or a bypassing of maskedPaths. This issue is fixed in versions 1.2.8, 1.3.3 and 1.4.0-rc.3.","published":"2025-11-06T18:47:47.335Z","modified":"2026-07-31T18:29:53.716040204Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/opencontainers/runc","fixedVersion":"1.2.8"},{"ecosystem":"Go","name":"github.com/opencontainers/runc","fixedVersion":"1.3.3"},{"ecosystem":"Go","name":"github.com/opencontainers/runc","fixedVersion":"1.4.0-rc.3"}],"fix":{"url":"https://github.com/opencontainers/runc/commit/1a30a8f3d921acbbb6a4bb7e99da2c05f8d48522","label":"opencontainers/runc@1a30a8f"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/31xxx/CVE-2025-31133.json"},{"type":"ADVISORY","url":"https://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-31133"},{"type":"FIX","url":"https://github.com/opencontainers/runc/commit/1a30a8f3d921acbbb6a4bb7e99da2c05f8d48522"},{"type":"FIX","url":"https://github.com/opencontainers/runc/commit/5d7b2424072449872d1cd0c937f2ca25f418eb66"},{"type":"FIX","url":"https://github.com/opencontainers/runc/commit/8476df83b534a2522b878c0507b3491def48db9f"},{"type":"FIX","url":"https://github.com/opencontainers/runc/commit/db19bbed5348847da433faa9d69e9f90192bfa64"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-31T18:29:53.716040204Z"}}