Medium severity · published Jul 6, 2026
CVE-2026-58402
Hugo default code block renderer XSS via unescaped code-fence language
5.4
CVSS
0.3%
EPSS
No
On KEV
Description
Hugo is a static site generator. From 0.60.0 until 0.163.3, Hugo's default code-block renderer wrote the Markdown code-fence language or info-string into the code class="language-…" data-lang="…" wrapper without HTML escaping. A fence info-string containing a quote and a script payload breaks out of the attribute and injects a live script element. This issue is fixed in 0.163.3.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 23% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
HU
hugo · gohugoio
>= 0.60.0, < 0.163.3 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-58402
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-58402
Patch
https://github.com/gohugoio/hugo/commit/ce1a7e0bce3713af40496ded3c2c0ceeed49231d
Issue Tracking
https://github.com/gohugoio/hugo/pull/15051
Release Notes
https://github.com/gohugoio/hugo/releases/tag/v0.163.3
Vendor Advisory
https://github.com/gohugoio/hugo/security/advisories/GHSA-q76j-gcg9-vxc6
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