Bug 2531978

Summary: CVE-2026-75926 hugo: Hugo 0.162.0 to 0.164.x - Node Permission Model Bypass via Default TailwindCSS Child-Process Grant [fedora-all]
Product: [Fedora] Fedora Reporter: aedmond
Component: hugoAssignee: Athos Ribeiro <athoscribeiro>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: urgent Docs Contact:
Priority: urgent    
Version: rawhideCC: athoscribeiro, epel-packagers-sig, go-sig, loranallensmith, neil, quantum.analyst, redhat
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["275c4623-b16e-482e-a66a-1ab1f4f142fb"]}
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2517977    

Description aedmond 2026-09-11 17:06:51 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

Hugo 0.161.0 placed the Node asset pipelines behind the Node.js permission model so that code running through PostCSS, Babel, or TailwindCSS could not reach the file system outside the project directory. Hugo 0.162.0 added tailwindcss to the AllowChildProcess default in config/security/securityConfig.go, which makes nodePermissionArgs in common/hexec/exec.go append --allow-child-process whenever the tool being launched is named tailwindcss. TailwindCSS loads the site's tailwind.config.js through require at startup, so top-level code in that file executes inside the permitted Node process and can call child_process to spawn a shell. The spawned process is not a Node process and inherits none of the permission flags, so it runs with the full privileges of the account performing the build. Building a site whose theme, module, or starter template supplies the Tailwind configuration therefore yields arbitrary command execution rather than the confined file access the permission model was introduced to enforce. Hugo 0.165.0 removes tailwindcss from the default security.exec.allow list, so the tool is no longer launched under the default configuration.