Hugo: Symlink confinement bypass in resources.Get

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-50135: 0.41% estimated exploitation activity in the next 30 days; percentile 35.41 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Commit: f8b5fa09a6 — Fix prevention of direct symlink reads in resources.Get Affected versions: v0.123.0 through v0.161.1. Earlier versions are not affected. Fixed in: v0.162.0. Severity: Medium. Requires the attacker to be able to place (or convince a site author to place) a symlink inside a mounted directory — for example, inside a locally-vendored theme under themes/. Themes mounted as Go modules from GitHub have symlinks stripped on download and are not affected. Multi-directory walks (e.g. content/asset walking) were not affected either; only direct lookups via resources.Get followed symlinks. Description. Hugo's virtual filesystem is designed so that files under a mount cannot reach outside the mount tree. A regression introduced in v0.123.0 caused RootMappingFs.statRoot to call Stat (which follows symlinks) instead of Lstat, so a direct resources.Get "somefile" where somefile was a symlink pointing outside the mount would return the target's contents. This effectively let a…

Published by the source

16 Jun 2026, 20:12 UTC

Last modified by the source

16 Jun 2026, 20:12 UTC

Source last checked

26 Oct 2026, 15:23 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-fw87-fv5r-9fpw

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-50135

Advisory: Hugo: Symlink confinement bypass in resources.Get
IDs: CVE-2026-50135, GHSA-fw87-fv5r-9fpw
Record: https://patchnext.com/advisories/cve-2026-50135 (revision 1, source checked 26 Oct 2026, 15:23 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/gohugoio/hugo 0.162.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/gohugoio/hugo: affected >= 0.123.0, < 0.162.0; fixed in 0.162.0

## Suggested inspection (read-only)
- Go github.com/gohugoio/hugo: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/gohugoio/hugo.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-fw87-fv5r-9fpw (GitHub-reviewed advisory GHSA-fw87-fv5r-9fpw lists affected ranges: Go github.com/gohugoio/hugo >=0.123.0 <0.162.0)

Commands are suggestions: review each one before running it.