Vulnerability in Hugo (CVE-2026-100690)
Summary
Vulnerability in Hugo (CVE-2026-100690). Confidential information can be exposed externally. Mitigation: upgrade to 0.166.0 or later.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-100690 has been found in Hugo.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: upgrade Hugo to 0.166.0 or later.
If unsure, ask your IT team or search "Hugo CVE-2026-100690" on the vendor's site.
CVE-2026-100690 (Hugo) — CWE-59 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 0.166.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-59) exists in Hugo.
Check the vendor advisory for the affected versions of Hugo.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
Update to 0.166.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Hugo' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'Hugo' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Hugoを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade Hugo to 0.166.0ステージング環境で 0.166.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-100690 hugo Fixed in: 0.166.0-1
- Ubuntu UBUNTU-CVE-2026-100690 hugo
References
- web github.com
- web vulncheck.com
- web nvd.nist.gov
- web github.com