CVE-2026-89259 Hugo before v0.165.0 Insufficient Permission Restriction via TailwindCSS
Hugo allows TailwindCSS to bypass permission restrictions, enabling file read/write outside the project directory during builds.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89259?
CVE-2026-89259 is a critical path traversal vulnerability in gohugoio hugo, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Hugo is a static site generator. From v0.161.0, Hugo executes Node tools under Node's permission model, but TailwindCSS — included in the default security.exec.allow list — requires a highly permissive configuration (--allow-addons, --allow-child-process, --allow-worker). As a result, the restrictions intended by the fix for GHSA-x597-9fr4-5857 could still be bypassed, allowing a Node tool invoked during a build to read and write files outside the project's working directory. Affected versions are those after v0.43; the issue was fixed in v0.165.0 by removing tailwindcss from the default security.exec.allow list. Users who do not use TailwindCSS, or who only build trusted sites, are not affected. As a workaround, users can define a restrictive security.exec.allow list in hugo.toml.
Weakness: CWE-250
Which versions are affected by CVE-2026-89259?
How do I fix CVE-2026-89259?
Upgrade to a fixed version.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-89259 being exploited?
There is no known exploitation of CVE-2026-89259 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-89259, GHSA-c34r-xm66-hh3p, GHSA-vrm6-x8vp-mv2r, MINI-4vfv-53c2-m43r, MINI-8r64-cmrq-49g2, UBUNTU-CVE-2026-89259.