{"id":"CVE-2026-58403","aliases":["GHSA-c3wq-j5vh-68rc"],"title":"Hugo: Symlink confinement bypass in os.ReadFile","summary":"Hugo: Symlink confinement bypass in os.ReadFile","severity":"medium","vendor":"gohugoio","product":"github.com/gohugoio/hugo","ecosystem":"go","affected":["github.com/gohugoio/hugo >= 0.123.0, < 0.163.1"],"patched":["github.com/gohugoio/hugo 0.163.1"],"published":"2026-06-19","updated":"2026-07-08","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-c3wq-j5vh-68rc","references":[{"url":"https://github.com/gohugoio/hugo/security/advisories/GHSA-c3wq-j5vh-68rc"},{"url":"https://github.com/gohugoio/hugo"}],"tags":["osv","go"],"epss":0.00475,"epssPercentile":0.40244,"ingestedAt":"2026-07-09T18:56:36.309Z","slug":"CVE-2026-58403","body":"## Overview\n\n**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`.\n\n## Affected packages\n\n- `github.com/gohugoio/hugo >= 0.123.0, < 0.163.1`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `github.com/gohugoio/hugo 0.163.1`","depth":"sunlit","depthScore":28,"depthScoreParts":{"impact":27.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}