CVE-2026-100693: Hugo v0.162.0 before v0.166.0 IP-literal Deny Rule Bypass

Severity: high (CVSS 8.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-26 · updated 2026-09-30
Weakness: CWE-178

Description

Hugo versions from v0.162.0 before v0.166.0 contain a case-sensitive validation flaw in the security.http.urls IP-literal deny rule that allows attackers to bypass restrictions. Attackers can use mixed-case URL schemes in resources.GetRemote calls to fetch from restricted IP addresses like localhost.

Affected products

gohugoio hugo: from 0.162.0 before 0.166.0 — fixed in 0.166.0

How to fix

Upgrade to a fixed version: gohugoio hugo 0.166.0. Check the vendor advisory for mitigations.

References

https://github.com/gohugoio/hugo/security/advisories/GHSA-pmrv-x7gp-2rjw
https://www.vulncheck.com/advisories/hugo-0.162.0-before-0.166.0-ip-literal-deny-rule-bypass

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