GHSA-vwg3-w8w3-pc79

Source

https://github.com/advisories/GHSA-vwg3-w8w3-pc79

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-vwg3-w8w3-pc79/GHSA-vwg3-w8w3-pc79.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-vwg3-w8w3-pc79

Aliases

Published

2026-08-19T19:32:38Z

Modified

2026-09-10T03:51:14Z

Severity

8.2 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N CVSS Calculator

Summary

Grav: .htaccess file extension rules bypass via case variation on case-insensitive filesystems

Details

Summary

The default .htaccess shipped with Grav (and the reference webserver-configs/htaccess.txt) contains security rules that block direct HTTP access to sensitive file types (.yaml, .yml, .php, .json, .twig, etc.) under user/ and system/vendor/ directories. However, these rules lack the [NC] (No Case) flag, making them case-sensitive. On case-insensitive filesystems (Windows/NTFS, macOS/HFS+, or Linux with Docker volumes mounted from Windows/macOS), an attacker can bypass these rules by requesting files with uppercase extensions (e.g., .YAML, .PHP, .JSON).

Affected Versions

Grav 2.0.1 (latest stable as of June 2026) — confirmed
Grav 1.7.x — likely affected (same .htaccess rules)
All versions shipping the current webserver-configs/htaccess.txt

Affected Component

File: .htaccess (root of Grav installation) Reference: webserver-configs/htaccess.txt

Affected Rules (lines 68, 70, 72)

# Line 68 — system/vendor file types
RewriteRule ^(system|vendor)/(.*)\.(txt|xml|md|html|htm|shtml|shtm|json|yaml|yml|php|php2|php3|php4|php5|phar|phtml|pl|py|cgi|twig|sh|bat)$ error [F]

# Line 70 — user file types
RewriteRule ^(user)/(.*)\.(txt|md|json|yaml|yml|php|php2|php3|php4|php5|phar|phtml|pl|py|cgi|twig|sh|bat)$ error [F]

# Line 72 — .md files globally
RewriteRule \.md$ error [F]

All three rules use [F] without [NC], making the extension match case-sensitive.

Steps to Reproduce

Install Grav on a system with a case-insensitive filesystem:
- Windows (native WAMP/XAMPP)
- macOS (default HFS+)
- Docker on Windows/macOS with volume mounts (e.g., ./data:/var/www/html)
Create or use any plugin that stores sensitive data in its YAML config (e.g., API keys):
```
user/plugins/my-plugin/my-plugin.yaml
```

Request the file with a case-varied extension:

GET /user/plugins/my-plugin/my-plugin.YAML HTTP/1.1

Expected: HTTP 403 Forbidden
Actual: HTTP 200 OK — full file contents returned, including any API keys or sensitive configuration

Impact

Information disclosure: Plugin configuration files (.yaml) containing API keys, credentials, or sensitive settings can be read by unauthenticated users
Source code exposure: PHP source files can be downloaded (instead of executed) when requested with .PHP extension on some configurations
Configuration exposure: user/config/system.yaml, user/config/site.yaml, and other system configuration files are accessible

Fix

Add the [NC] flag to the three affected rules:

RewriteRule ^(system|vendor)/(.*)\.(txt|xml|md|html|htm|shtml|shtm|json|yaml|yml|php|php2|php3|php4|php5|phar|phtml|pl|py|cgi|twig|sh|bat)$ error [F,NC]
RewriteRule ^(user)/(.*)\.(txt|md|json|yaml|yml|php|php2|php3|php4|php5|phar|phtml|pl|py|cgi|twig|sh|bat)$ error [F,NC]
RewriteRule \.md$ error [F,NC]

The [NC] flag makes the extension matching case-insensitive, covering .YAML, .Yaml, .PHP, .Json, etc.

Mitigating Factors

On native Linux with ext4 filesystem (case-sensitive), the attack does not work because Apache cannot resolve the uppercase filename to the actual file
Grav 2.0's Twig sandbox blocks access to plugins config subtree from page content, preventing SSTI-based config exfiltration
The user/accounts/, user/config/, and user/data/ folders have separate rules (line 62, 66) that block ALL file types regardless of extension — these are not affected

Environment

Grav: 2.0.1
PHP: 8.3
Apache: 2.4 with mod_rewrite
OS: Docker (php:8.3-apache) with volume mounted from Windows 10 (NTFS)
Tested: June 2026

Reporter

Sisnetic

Database specific

{
    "cwe_ids":  [
        "CWE-178"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-08-19T19:32:38Z",
    "nvd_published_at":  "2026-08-19T16:18:20Z",
    "severity":  "HIGH"
}

References

Affected packages

Packagist / getgrav/grav

Package

Name: getgrav/grav
Purl: pkg:composer/getgrav/grav

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

2.0.4

Affected versions

0.*

0.8.0

0.9.0

0.9.1

0.9.2

0.9.3

0.9.4

0.9.5

0.9.6

0.9.7

0.9.8

0.9.9

0.9.10

0.9.11

0.9.12

0.9.13

0.9.14

0.9.15

0.9.16

0.9.17

0.9.18

0.9.19

0.9.20

0.9.21

0.9.22

0.9.23

0.9.24

0.9.25

0.9.26

0.9.27

0.9.28

0.9.29

0.9.30

0.9.31

0.9.32

0.9.33

0.9.34

0.9.35

0.9.36

0.9.37

0.9.38

0.9.39

0.9.40

0.9.41

0.9.42

0.9.43

0.9.44

0.9.45

1.*

1.0.0-rc.1

1.0.0-rc.2

1.0.0-rc.3

1.0.0-rc.4

1.0.0-rc.5

1.0.0-rc.6

1.0.0

1.0.1

1.0.2

1.0.3

1.0.4

1.0.5

1.0.6

1.0.7

1.0.8

1.0.9

1.0.10

1.1.0-beta.1

1.1.0-beta.2

1.1.0-beta.3

1.1.0-beta.4

1.1.0-beta.5

1.1.0-rc.1

1.1.0-rc.2

1.1.0-rc.3

1.1.0

1.1.1

1.1.2

1.1.3

1.1.4

1.1.5

1.1.6

1.1.7

1.1.8

1.1.9-rc.1

1.1.9-rc.2

1.1.9-rc.3

1.1.9

1.1.10

1.1.11

1.1.12

1.1.13

1.1.14

1.1.15

1.1.16

1.1.17

1.2.0-rc.1

1.2.0-rc.2

1.2.0-rc.3

1.2.0

1.2.1

1.2.2

1.2.3

1.2.4

1.3.0-rc.1

1.3.0-rc.2

1.3.0-rc.3

1.3.0-rc.4

1.3.0-rc.5

1.3.0

1.3.1

1.3.2

1.3.3

1.3.4

1.3.5

1.3.6

1.3.7

1.3.8

1.3.9

1.3.10

1.4.0-beta.1

1.4.0-beta.2

1.4.0-beta.3

1.4.0-rc.1

1.4.0-rc.2

1.4.0

1.4.1

1.4.2

1.4.3

1.4.4

1.4.5

1.4.6

1.4.7

1.4.8

1.5.0-beta.1

1.5.0-beta.2

1.5.0-rc.1

1.5.0

1.5.1

1.5.2

1.5.3

1.5.4

1.5.5

1.5.6

1.5.7

1.5.8

1.5.9

1.5.10

1.6.0-beta.1

1.6.0-beta.2

1.6.0-beta.3

1.6.0-beta.4

1.6.0-beta.5

1.6.0-beta.6

1.6.0-beta.7

1.6.0-beta.8

1.6.0-rc.1

1.6.0-rc.2

1.6.0-rc.3

1.6.0-rc.4

1.6.0

1.6.1

1.6.2

1.6.3

1.6.4

1.6.5

1.6.6

1.6.7

1.6.8

1.6.9

1.6.10

1.6.11

1.6.12

1.6.13

1.6.14

1.6.15

1.6.16

1.6.17

1.6.18

1.6.19

1.6.20

1.6.21

1.6.22

1.6.23

1.6.24

1.6.25

1.6.26

1.6.27

1.6.28

1.6.29

1.6.30

1.6.31

1.7.0-beta.1

1.7.0-beta.2

1.7.0-beta.3

1.7.0-beta.4

1.7.0-beta.5

1.7.0-beta.6

1.7.0-beta.7

1.7.0-beta.8

1.7.0-beta.9

1.7.0-beta.10

1.7.0-rc.1

1.7.0-rc.2

1.7.0-rc.3

1.7.0-rc.4

1.7.0-rc.5

1.7.0-rc.6

1.7.0-rc.7

1.7.0-rc.8

1.7.0-rc.9

1.7.0-rc.10

1.7.0-rc.11

1.7.0-rc.12

1.7.0-rc.13

1.7.0-rc.14

1.7.0-rc.15

1.7.0-rc.16

1.7.0-rc.17

1.7.0-rc.18

1.7.0-rc.19

1.7.0-rc.20

1.7.0

1.7.1

1.7.3

1.7.4

1.7.5

1.7.6

1.7.7

1.7.8

1.7.9

1.7.10

1.7.12

1.7.13

1.7.14

1.7.15

1.7.16

1.7.17

1.7.18

1.7.19

1.7.20

1.7.21

1.7.22

1.7.23

1.7.24

1.7.25

1.7.26

1.7.26.1

1.7.27

1.7.27.1

1.7.28

1.7.29

1.7.29.1

1.7.30

1.7.31

1.7.32

1.7.33

1.7.34

1.7.35

1.7.36

1.7.37

1.7.37.1

1.7.38

1.7.39

1.7.39.1

1.7.39.2

1.7.39.3

1.7.39.4

1.7.40

1.7.41

1.7.41.1

1.7.41.2

1.7.42

1.7.42.1

1.7.42.2

1.7.42.3

1.7.43

1.7.44

1.7.45

1.7.46

1.7.47

1.7.48

1.7.49

1.7.49.1

1.7.49.2

1.7.49.3

1.7.49.4

1.7.49.5

1.7.51

1.7.52

1.7.53

1.7.53.1

1.7.53.2

1.7.53.3

1.8.0-beta.1

1.8.0-beta.2

1.8.0-beta.3

1.8.0-beta.4

1.8.0-beta.5

1.8.0-beta.6

1.8.0-beta.7

1.8.0-beta.8

1.8.0-beta.9

1.8.0-beta.10

1.8.0-beta.11

1.8.0-beta.12

1.8.0-beta.13

1.8.0-beta.14

1.8.0-beta.15

1.8.0-beta.16

1.8.0-beta.17

1.8.0-beta.18

1.8.0-beta.19

1.8.0-beta.20

1.8.0-beta.21

1.8.0-beta.22

1.8.0-beta.23

1.8.0-beta.24

1.8.0-beta.25

1.8.0-beta.26

1.8.0-beta.27

1.8.0-beta.28

1.8.0-beta.29

2.*

2.0.0-beta.1

2.0.0-beta.2

2.0.0-beta.3

2.0.0-beta.4

2.0.0-rc.1

2.0.0-rc.2

2.0.0-rc.3

2.0.0-rc.4

2.0.0-rc.5

2.0.0-rc.6

2.0.0-rc.7

2.0.0-rc.8

2.0.0-rc.9

2.0.0-rc.10

2.0.0

2.0.1

2.0.2

2.0.3

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-vwg3-w8w3-pc79/GHSA-vwg3-w8w3-pc79.json"