CVE-2026-100690
Description
A flaw was found in Hugo. This vulnerability allows information disclosure when Hugo executes build tools under the Node.js permission model, which validates only lexical file paths and fails to restrict symbolic links pointing outside the sandbox. An attacker capable of contributing content to a repository can exploit this by committing a symbolic link targeting sensitive host files alongside a build tool that reads it. Consequently, files readable by the build process can be exposed and embedded into the published site.
Statement
This vulnerability is rated as Moderate impact because successful exploitation requires processing an untrusted project or pull request that specifically utilizes Node.js asset pipelines. Although an attacker could expose sensitive local files accessible to the builder by introducing malicious symlinks into the source tree, this flaw cannot be exploited remotely without direct user interaction or automated build triggers. Build systems and projects that only process trusted content or do not invoke Node.js asset transformations are not at risk.
Mitigation
To mitigate this issue, implement the following operational controls:
1. Avoid processing untrusted pull requests, themes, or repository branches that execute Node.js transformation pipelines (such as PostCSS, TailwindCSS, or Babel). Builds that do not execute Node.js tools are unaffected.
2. Isolate Hugo builds inside dedicated containers or ephemeral sandboxes that have no sensitive host directories or files mounted, and run the build process with minimal privileges.
Caveat: Disabling or avoiding Node.js asset transformations may prevent custom stylesheets or scripts from compiling properly, which can alter the appearance or functionality of the generated site.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | N/A | 7.5 |
| Attack Vector | Local | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality,Integrity,Access Control
Technical Impact: Read Files or Directories; Modify Files or Directories; Bypass Protection Mechanism
An attacker may be able to traverse the file system to unintended locations and read or overwrite the contents of unexpected files. If the files are used for a security mechanism then an attacker may be able to bypass the mechanism.
Other
Technical Impact: Execute Unauthorized Code or Commands
Windows simple shortcuts, sometimes referred to as soft links, can be exploited remotely since a ".LNK" file can be uploaded like a normal file. This can enable remote execution.
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