Bug 2541815 (CVE-2026-100690)

Summary:	CVE-2026-100690 github.com/gohugoio/hugo: Hugo: Arbitrary file read via symbolic link sandbox escape
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	anjoseph, eglynn, jjoyce, jprabhak, jpretori, jschluet, lchilton, lhh, mburns, mgarciac, rhel-process-autobot, sfeifer, watson-tool-maintainers, wtam
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in Hugo. This vulnerability allows information disclosure when Hugo executes build tools under the Node.js permission model, which validates only lexical file paths and fails to restrict symbolic links pointing outside the sandbox. An attacker capable of contributing content to a repository can exploit this by committing a symbolic link targeting sensitive host files alongside a build tool that reads it. Consequently, files readable by the build process can be exposed and embedded into the published site.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
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Description OSIDB Bzimport 2026-09-26 13:32:15 UTC

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.