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TI-2026-64847 Aliases CVE-2026-100691GHSA-8v94-8989-vc79

Hugo before 0.166.0 Stored XSS via lineAnchors code block option

Priority LOW 22CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
None · None · None
Fix status
Partial Red Hat: 1 fixed, 3 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-79.

Summary

Hugo versions 0.75.0 through 0.165.x contain a stored cross-site scripting vulnerability: the syntax highlighter does not escape the `lineAnchors` option before passing it to Chroma, which writes the value verbatim into the `id` and `href` attributes of the generated line-number markup. A crafted `lineAnchors` value supplied as a Markdown code fence attribute (or passed to the `highlight` template function) results in unescaped HTML in the rendered page, allowing arbitrary JavaScript to execute in the browsers of visitors to the generated site. This affects sites that build and publish Markdown from untrusted contributors; Hugo's security model otherwise considers content trusted input. Fixed in 0.166.0, where the `lineAnchors` value is HTML-escaped before being passed to Chroma.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00172 6th percentileScored 2026-11-07
Fix Partial hugo (gohugoio): 0.166.0Red Hat: 1 advisoryRed Hat: 1 fixed, 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
gohugoiohugo0.75.0 to before 0.166.00.166.0Patch availableCNA
  • hugo Vendorgohugoio Affected 0.75.0 to before 0.166.0 Fixed in 0.166.0 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:gohugo:hugo:*:*:*:*:*:*:*:*0.75.0 to before 0.166.0Vulnerablegohugoio
  • cpe:2.3:a:gohugo:hugo:*:*:*:*:*:*:*:* Versions 0.75.0 to before 0.166.0 Vulnerable ·gohugoio

Remediation

  • Fix · CNA hugo (gohugoio) Fixed in 0.166.0

Red Hat 1 advisory

  • RHSA-2026:66266 Released 2026-09-09 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images hugo-0.166.0-0.1.hum1@aarch64, hugo-0.166.0-0.1.hum1@src, hugo-0.166.0-0.1.hum1@x86_64

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    gohugoio hugo 0.166.0

    5 records Highest priority Priority MEDIUM 2 MEDIUM, 3 LOW

    Other records, highest priority first

    • TI-2026-64848 Hugo before v0.166.0 Path Traversal via Symlinked Mount RootsPriority MEDIUM 44
    • TI-2026-64846 Hugo v0.161.0 to v0.165.0 Arbitrary File Read via SymlinksPriority MEDIUM 44
    • TI-2026-64849 Hugo v0.162.0 before v0.166.0 IP-literal Deny Rule BypassPriority LOW 38
    Show all 5 records →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat OpenShift GitOpsAffectedNo fix yet: Fix deferred
Red Hat OpenStack Platform 18.0AffectedNo fix yet: Fix deferred
Red Hat Hardened ImagesFixed RHSA-2026:66266
Not affected: 1 product
  • Red Hat Hardened Images

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-100691
  2. 2026-10-03 Alias added: GHSA-8v94-8989-vc79

References

Advisory 1

  • TI-2026-64848 Hugo before v0.166.0 Path Traversal via Symlinked Mount Roots CVSS 4.0HIGH 8.7
  • TI-2026-64846 Hugo v0.161.0 to v0.165.0 Arbitrary File Read via Symlinks CVSS 4.0HIGH 8.7
  • TI-2026-53153 Hugo 0.162.0 to 0.164.x - Node Permission Model Bypass via Default TailwindCSS Child-Process Grant CVSS 4.0CRITICAL 9.3
  • TI-2020-16105 Hugo can execute a binary from the current directory on Windows CVSS 3.1HIGH 8.5
  • TI-2026-64849 Hugo v0.162.0 before v0.166.0 IP-literal Deny Rule Bypass CVSS 4.0HIGH 8.6
  • TI-2026-32270 Hugo: Node tool execution allows file system access outside the project directory CVSS 4.0MEDIUM 6.2
See all 15 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences