Hugo versions from v0.161.0 through v0.165.0 run Node.js tools (css.PostCSS, css.TailwindCSS, js.Babel) under the Node.js permission model to restrict file system reads to the project directory and configured mounts. Because the Node.js permission model validates only the lexical path and follows symbolic links that point outside the allowed set, Hugo did not detect symlinks escaping the sandbox. An attacker who can contribute content to a Hugo project (for example via a pull request) can commit a symlink such as assets/css/x.css -> /etc/passwd together with a PostCSS plugin that reads it, allowing any file readable by the Hugo build process to be disclosed and potentially embedded in the published site. This affects builds using the default security configuration; projects that do not invoke Node.js tools are unaffected. Fixed in v0.166.0, which scans allowed paths and fails the build when a symbolic link resolves outside them.
Hugo v0.161.0 to v0.165.0 Arbitrary File Read via Symlinks
Problem type
Affected products
gohugoio
< 0.166.0 - AFFECTED
0.166.0 - UNAFFECTED
References
https://github.com/gohugoio/hugo/security/advisories/GHSA-x3mx-cm49-8m9c
https://www.vulncheck.com/advisories/hugo-0.161.0-to-0.165.0-arbitrary-file-read-via-symlinks
GitHub Security Advisories
GHSA-gqg5-5gw3-54pq
Hugo versions from v0.161.0 through v0.165.0 run Node.js tools (css.PostCSS, css.TailwindCSS, js...
https://github.com/advisories/GHSA-gqg5-5gw3-54pqHugo versions from v0.161.0 through v0.165.0 run Node.js tools (css.PostCSS, css.TailwindCSS, js.Babel) under the Node.js permission model to restrict file system reads to the project directory and configured mounts. Because the Node.js permission model validates only the lexical path and follows symbolic links that point outside the allowed set, Hugo did not detect symlinks escaping the sandbox. An attacker who can contribute content to a Hugo project (for example via a pull request) can commit a symlink such as assets/css/x.css -> /etc/passwd together with a PostCSS plugin that reads it, allowing any file readable by the Hugo build process to be disclosed and potentially embedded in the published site. This affects builds using the default security configuration; projects that do not invoke Node.js tools are unaffected. Fixed in v0.166.0, which scans allowed paths and fails the build when a symbolic link resolves outside them.
https://github.com/gohugoio/hugo/security/advisories/GHSA-x3mx-cm49-8m9c
https://nvd.nist.gov/vuln/detail/CVE-2026-100690
https://www.vulncheck.com/advisories/hugo-0.161.0-to-0.165.0-arbitrary-file-read-via-symlinks
https://github.com/advisories/GHSA-gqg5-5gw3-54pq
JSON source
https://cveawg.mitre.org/api/cve/CVE-2026-100690Click to expand
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"assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
"assignerShortName": "VulnCheck",
"dateUpdated": "2026-09-26T13:23:49.448Z",
"dateReserved": "2026-09-26T02:37:41.037Z",
"datePublished": "2026-09-26T13:23:49.448Z",
"state": "PUBLISHED"
},
"containers": {
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"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
"shortName": "VulnCheck",
"dateUpdated": "2026-09-26T13:23:49.448Z"
},
"datePublic": "2026-09-09T00:00:00.000Z",
"title": "Hugo v0.161.0 to v0.165.0 Arbitrary File Read via Symlinks",
"descriptions": [
{
"lang": "en",
"value": "Hugo versions from v0.161.0 through v0.165.0 run Node.js tools (css.PostCSS, css.TailwindCSS, js.Babel) under the Node.js permission model to restrict file system reads to the project directory and configured mounts. Because the Node.js permission model validates only the lexical path and follows symbolic links that point outside the allowed set, Hugo did not detect symlinks escaping the sandbox. An attacker who can contribute content to a Hugo project (for example via a pull request) can commit a symlink such as assets/css/x.css -> /etc/passwd together with a PostCSS plugin that reads it, allowing any file readable by the Hugo build process to be disclosed and potentially embedded in the published site. This affects builds using the default security configuration; projects that do not invoke Node.js tools are unaffected. Fixed in v0.166.0, which scans allowed paths and fails the build when a symbolic link resolves outside them."
}
],
"affected": [
{
"vendor": "gohugoio",
"product": "hugo",
"defaultStatus": "unaffected",
"versions": [
{
"version": "0.161.0",
"status": "affected",
"versionType": "semver",
"lessThan": "0.166.0"
},
{
"version": "0.166.0",
"status": "unaffected",
"versionType": "semver"
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],
"problemTypes": [
{
"descriptions": [
{
"lang": "en",
"description": "Improper Link Resolution Before File Access ('Link Following')",
"cweId": "CWE-59",
"type": "CWE"
}
]
}
],
"references": [
{
"url": "https://github.com/gohugoio/hugo/security/advisories/GHSA-x3mx-cm49-8m9c",
"name": "GitHub Security Advisory (GHSA-x3mx-cm49-8m9c)",
"tags": [
"vendor-advisory"
]
},
{
"url": "https://www.vulncheck.com/advisories/hugo-0.161.0-to-0.165.0-arbitrary-file-read-via-symlinks",
"name": "VulnCheck Advisory: Hugo v0.161.0 to v0.165.0 Arbitrary File Read via Symlinks",
"tags": [
"third-party-advisory"
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}
],
"metrics": [
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"format": "CVSS"
},
{
"format": "CVSS",
"cvssV3_1": {
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"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"availabilityImpact": "NONE",
"baseScore": 7.5,
"baseSeverity": "HIGH"
}
}
],
"credits": [
{
"lang": "en",
"value": "DONG2209",
"type": "finder"
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}
}
}