{"id":"CVE-2026-44973","aliases":["GHSA-qw64-3x98-g7q2","GO-2026-5597"],"url":"https://o3.security/vulnerability/CVE-2026-44973","summary":"Billy: Path traversal vulnerabilities","details":"### Impact\nMultiple path traversal issues exist across different components of `go-billy`. Insufficient path sanitization and boundary enforcement may allow crafted paths (e.g., using `..`) to escape intended base directories.\n\nWhile go-billy was not originally designed to provide a strong security boundary, some of these issues were inconsistent across some of the built-in implementations. This results in scenarios where applications relying on `go-billy` for some level of isolation may inadvertently expose access to unintended filesystem locations.\n\nThe `osfs.ChrootOS` implementation is notably affected by this vulnerability and is now deprecated in `v5`, removed at `v6`. Users are recommended to move on to `osfs.BoundOS` instead: `osfs.New(path, WithBoundOS())`.\n\nUsers requiring stronger security boundary enforcement are recommended to upgrade to `v6`, where the `osfs` implementation are backed by the [traversal-resistant](https://go.dev/blog/osroot) primitive [os.Root](https://pkg.go.dev/os#Root).\n\n### Patches\nUsers should upgrade to a patched version in order to mitigate this vulnerability. Versions prior to `v5` are likely to be affected, users are recommended to upgrade to a supported `go-billy` version.\n\n### Credits\nThanks to @faran66 and @vnykmshr for finding and separately reporting this issue privately to the go-git project. 🙇","published":"2026-05-28T21:26:14.734Z","modified":"2026-08-27T18:26:15.508693758Z","cvss":{"score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"},"epss":{"score":0.0031,"percentile":0.2316,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/go-git/go-billy/v5","fixedVersion":"5.9.0"},{"ecosystem":"Go","name":"github.com/go-git/go-billy/v6","fixedVersion":"6.0.0-alpha.1"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44973.json"},{"type":"ADVISORY","url":"https://github.com/go-git/go-billy/security/advisories/GHSA-qw64-3x98-g7q2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44973"},{"type":"PACKAGE","url":"https://github.com/go-git/go-billy"},{"type":"WEB","url":"https://github.com/go-git/go-billy/releases/tag/v5.9.0"},{"type":"WEB","url":"https://github.com/go-git/go-billy/releases/tag/v6.0.0-alpha.1"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-27T18:26:15.508693758Z"}}