How severe is CVE-2026-56394?

No CVSS score has been assigned to CVE-2026-56394 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-56394?

CVE-2026-56394 affects the following packages: craftcms/cms (Packagist), craftcms/cms (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2026-56394?

Update craftcms/cms to 4.17.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-56394 is resolved across your whole dependency graph.

How do I detect CVE-2026-56394 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for craftcms/cms. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-56394 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-56394?

O3 pinpoints whether CVE-2026-56394 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-56394 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-56394 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What type of vulnerability is CVE-2026-56394?

CVE-2026-56394 is classified as Path Traversal (CWE-22). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-56394 published, and has it been updated?

CVE-2026-56394 was published on June 21, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

Not in CISA KEV

CVE-2026-56394

Fix: craftcms/cms@30f5f1a

CVE-2026-56394 is a Path Traversal vulnerability in craftcms/cms. O3 Security confirms whether CVE-2026-56394 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Craft CMS - Authenticated Path Traversal in assets/icon Extension Parameter

Also known asGHSA-c43v-4cr8-6mvp

Published

Jun 21, 2026

Updated

Aug 12, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Aug 12, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

2 pkgs affected

🐘craftcms/cms🐘craftcms/cms

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Craft CMS from 4.0.0-RC1 contains an authenticated path traversal vulnerability in the assets/icon endpoint where the extension parameter is not validated before file existence checks. Attackers can bypass extension validation by passing traversal sequences that resolve to existing SVG files, allowing local file read access.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`craftcms/cms`	≥ 4.0.0-RC1&&< 4.17.7	4.17.7
🐘Packagist	`craftcms/cms`	≥ 5.0.0-RC1&&< 5.9.13	5.9.13

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for craftcms/cms. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update craftcms/cms to 4.17.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-56394 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-56394 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-56394. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2026-56394 in your dependencies?

O3 detects CVE-2026-56394 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works