CVE-2026-56394: Craftcms/cms Path Traversal Vulnerability

LOW
Advisory Identifier: GHSA-c43v-4cr8-6mvp
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CWE-22
Published
Advisory Summary

CVE-2026-56394 is a LOW path traversal vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Craftcms/cms libraries in the Packagist ecosystem. The issue involves craft cms has authenticated path traversal in `assets/icon`, allowing local `.svg` file read. Remediation is available by upgrading affected packages to version 4.17.7, 5.9.13.

CVE-2026-56394 at a Glance

CVE Identifier CVE-2026-56394
GHSA Identifier GHSA-c43v-4cr8-6mvp
Severity LOW
CVSS v3.1 Base Score N/A
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Craftcms/cms
Package Ecosystem Packagist
Published Date
Last Updated

How to Fix CVE-2026-56394

To remediate this vulnerability, upgrade all affected Craftcms/cms dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

craftcms/cms fixed: 4.17.7 
Upgrade craftcms/cms to 4.17.7
craftcms/cms fixed: 5.9.13 
Upgrade craftcms/cms to 5.9.13
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for craftcms/cms

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-56394, inspect your project dependencies for Craftcms/cms:

inspect dependencies for craftcms/cms

Analyze the terminal output to locate any version of Craftcms/cms in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.17.7), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. In Craftcms/cms, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary An authenticated path traversal in `assets/icon` allows local SVG file read by passing traversal sequences in the `extension` parameter. The issue is caused by file existence checks happening before extension validation. ### Details The endpoint: - `src/controllers/AssetsController.php:1115-1123` - `actionIcon(string $extension)` calls `Assets::iconPath($extension)` and returns `sendFile($path, ...)`. In `Assets::iconPath()`: - Path is built from user-controlled `extension`: - `src/helpers/Assets.php:906-909` - If `file_exists($path)` is true, path is returned immediately: - `src/helpers/Assets.php:910-912` Validation exists in `Assets::iconSvg()`: - `preg_match('/^\w+$/', $extension)` - `src/helpers/Assets.php:927-931` However, that validation is only reached if `iconPath()` does **not** find a file. So traversal payloads that resolve to existing `.svg` files bypass validation and are served by `sendFile()`. ### Impact - Authenticated users can read local .svg files accessible to the application process. ### References - https://github.com/craftcms/cms/commit/30f5f1a8d6edf0f3a00be72c42c78d9dc7d72d5c

CVE-2026-56394 Affected Craftcms/cms Versions

2 component(s)
Fixed Versions:
4.17.75.9.13
Product / Package Ecosystem Affected Versions Fixed Version
craftcms/cms
 Packagist
≥ 4.0.0-RC1
< 4.17.7
4.17.7
craftcms/cms
 Packagist
≥ 5.0.0-RC1
< 5.9.13
5.9.13

References

GitHub Advisory / Wiki ADVISORY
https://github.com/craftcms/cms/security/advisories/GHSA-c43v-4cr8-6mvp
NVD — CVE-2026-56394 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-56394
Security Fix Commit FIX COMMIT
https://github.com/craftcms/cms/commit/30f5f1a8d6edf0f3a00be72c42c78d9dc7d72d5c
Craftcms/cms Source Repository REPOSITORY
https://github.com/craftcms/cms
www.vulncheck.com/advisories/craft-cm... WEB
https://www.vulncheck.com/advisories/craft-cms-authenticated-path-traversal-in-assets-icon-extension-parameter

Frequently Asked Questions

What is CVE-2026-56394?
CVE-2026-56394 is a security vulnerability in Craftcms/cms involving Craft CMS has authenticated path traversal in `assets/icon`, allowing local `.svg` file read under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Craftcms/cms versions are affected?
Affected versions include releases prior to 4.17.7, 5.9.13 across affected packages: craftcms/cms.
What version fixes CVE-2026-56394?
Upgrading to 4.17.7, 5.9.13 (or the latest patched release for your respective branch) resolves the vulnerability.
Is craftcms/cms affected?
Yes, craftcms/cms is affected in releases prior to 4.17.7, 5.9.13. Upgrade your dependency to 4.17.7, 5.9.13 or later.
What CWE is associated with CVE-2026-56394?
CVE-2026-56394 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.).
How can I check Packagist dependencies for CVE-2026-56394?
Run the dependency tree command: 'inspect dependencies for craftcms/cms'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-c43v-4cr8-6mvp",
  "modified" : "2026-08-06T21:58:07Z",
  "published" : "2026-07-09T13:44:06Z",
  "aliases" : [ "CVE-2026-56394" ],
  "summary" : "Craft CMS has authenticated path traversal in `assets/icon`, allowing local `.svg` file read",
  "details" : "### Summary\n\nAn authenticated path traversal in `assets/icon` allows local SVG file read by passing traversal sequences in the `extension` parameter. The issue is caused by file existence checks happening before extension validation.\n\n### Details\nThe endpoint:\n- `src/controllers/AssetsController.php:1115-1123`\n- `actionIcon(string $extension)` calls `Assets::iconPath($extension)` and returns `sendFile($path, ...)`.\n\nIn `Assets::iconPath()`:\n- Path is built from user-controlled `extension`:\n  - `src/helpers/Assets.php:906-909`\n- If `file_exists($path)` is true, path is returned immediately:\n  - `src/helpers/Assets.php:910-912`\n\nValidation exists in `Assets::iconSvg()`:\n  - `preg_match('/^\\w+$/', $extension)`\n  - `src/helpers/Assets.php:927-931`\n\nHowever, that validation is only reached if `iconPath()` does **not** find a file.\nSo traversal payloads that resolve to existing `.svg` files bypass validation and are served by `sendFile()`.\n\n### Impact\n\n- Authenticated users can read local .svg files accessible to the application process.\n\n### References\n\n- https://github.com/craftcms/cms/commit/30f5f1a8d6edf0f3a00be72c42c78d9dc7d72d5c",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "craftcms/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0-RC1"
      }, {
        "fixed" : "4.17.7"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 4.17.6"
    }
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "craftcms/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.0.0-RC1"
      }, {
        "fixed" : "5.9.13"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 5.9.12"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/security/advisories/GHSA-c43v-4cr8-6mvp"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-56394"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/commit/30f5f1a8d6edf0f3a00be72c42c78d9dc7d72d5c"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/craftcms/cms"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/craft-cms-authenticated-path-traversal-in-assets-icon-extension-parameter"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-09T13:44:06Z",
    "nvd_published_at" : null
  }
}