---
id: CVE-2026-100669
title: >-
  Grav before 2.0.25 ships web server configuration samples whose access-control
  deny rules are matched case-sensitively
summary: >-
  Grav before 2.0.25 ships web server configuration samples whose access-control
  deny rules are matched case-sensitively. In webserver-configs/web.config
  (IIS), every deny rule (user_sensitive_folders, user_accounts, user_data,
  user_error_…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-178
vendor: getgrav
product: grav
affected:
  - grav < 2.0.25
published: '2026-09-26'
updated: '2026-09-26'
sourceUpdated: '2026-09-26T14:16:50.540'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-100669'
references:
  - url: 'https://github.com/getgrav/grav/security/advisories/GHSA-pg8v-xw58-frq8'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/grav-before-2.0.25-sensitive-file-disclosure-via-case-variation-bypass
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-26T13:33:20.912Z'
---

## Overview

Grav before 2.0.25 ships web server configuration samples whose access-control deny rules are matched case-sensitively. In webserver-configs/web.config (IIS), every deny rule (user_sensitive_folders, user_accounts, user_data, user_error_redirect, user_pages, system, vendor, ignore_folders) sets ignoreCase="false" on its URL Rewrite <match> element, overriding the IIS default of ignoreCase="true"; because these are rewrite matches rather than <requestFiltering> elements, there is no case-insensitive fallback. On IIS running over case-insensitive NTFS, an unauthenticated remote attacker can vary the case of a folder name or file extension (for example GET /user/CONFIG/system.YAML) so that no deny rule matches and the IIS static file handler resolves and returns the underlying file, disclosing sensitive data such as configuration secrets or account password hashes. Whether a bypassed file is actually returned depends on MIME registration: .json is served by default, while .yaml/.yml return HTTP 404.3 on a stock IIS unless a YAML MIME mapping has been added. The same class of gap exists in the bundled webserver-configs/lighttpd.conf, whose user/(config|env), directory, script-extension, root-file and dotfile rules lack the (?i) modifier, though it is lower risk because lighttpd typically runs on case-sensitive filesystems. Deployments served by Apache (.htaccess), nginx, Caddy, or the PHP built-in server are not affected. The issue is fixed in 2.0.25; because the .htaccess installer heal does not touch web.config or lighttpd.conf, operators must re-copy the corrected sample files after upgrading.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.