CVE-2026-109597: Hugo v0.60.0 before v0.167.0 Stored XSS via Table of Contents Heading IDs

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-12 · updated 2026-10-16
Weakness: CWE-79

Description

Hugo from v0.60.0 before v0.167.0 contains a stored cross-site scripting vulnerability that allows Markdown content authors to inject HTML by supplying crafted explicit heading IDs. Attackers can break out of the unescaped href attribute in .TableOfContents or .Fragments.ToHTML output to inject elements with event handlers into rendered pages.

Affected products

gohugoio hugo: from 0.60.0 before 0.167.0 — fixed in 0.167.0

How to fix

Upgrade to a fixed version: gohugoio hugo 0.167.0. Check the vendor advisory for mitigations.

References

https://github.com/gohugoio/hugo/security/advisories/GHSA-wcpj-vcvm-j4pg
https://www.vulncheck.com/advisories/hugo-0.60.0-before-0.167.0-stored-xss-via-table-of-contents-heading-ids

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