{"id":"GHSA-c3wq-j5vh-68rc","summary":"Hugo: Symlink confinement bypass in os.ReadFile","details":"**Affected versions:** v0.123.0 through v0.163.0. Earlier versions are not affected.\n**Fixed in:** v0.163.1.\n**Severity:** Medium. Requires the attacker to be able to place (or convince a site author to place) a symlink inside a mounted directory — for example, inside a locally-vendored theme under `themes/`. Themes mounted as Go modules from GitHub have symlinks stripped on download and are not affected. Multi-directory walks (e.g. content/asset walking) were not affected either; only direct lookups via `resources.Get` followed symlinks.\n\n**Description.** Hugo's virtual filesystem is designed so that files under a mount cannot reach outside the mount tree. A regression introduced in v0.123.0 caused `RootMappingFs.statRoot` to call `Stat` (which follows symlinks) instead of `Lstat`, so a direct `os.ReadFile \"somefile\"` where `somefile` was a symlink pointing outside the mount would return the target's contents. This effectively let a symlink planted inside a theme or local mount read arbitrary files reachable to the user running `hugo`.","aliases":["CVE-2026-58403","GO-2026-5309"],"modified":"2026-07-24T19:26:07.133083697Z","published":"2026-06-19T17:45:38Z","database_specific":{"nvd_published_at":null,"cwe_ids":["CWE-59"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-06-19T17:45:38Z"},"references":[{"type":"WEB","url":"https://github.com/gohugoio/hugo/security/advisories/GHSA-c3wq-j5vh-68rc"},{"type":"PACKAGE","url":"https://github.com/gohugoio/hugo"}],"affected":[{"package":{"name":"github.com/gohugoio/hugo","ecosystem":"Go","purl":"pkg:golang/github.com/gohugoio/hugo"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.123.0"},{"fixed":"0.163.1"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-c3wq-j5vh-68rc/GHSA-c3wq-j5vh-68rc.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N"}]}