CVE-2026-72779 — craftcms/cms
Fix: craftcms/cms@7c96fd7CVE-2026-72779 is a CWE-184 vulnerability in craftcms/cms. A fix is available for craftcms/cms — see the affected versions and patch details below.
Craft CMS 5.0.0-RC1 before 5.10.6 Arbitrary File Read via SplFileObject
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-72779.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
craftcms/cms🐘craftcms/cmsReal-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
The create() Twig function (introduced in 5.9.0) allows instantiation of arbitrary PHP classes from template code, restricted only by a 5-entry blocklist. SplFileObject is not in the blocklist, enabling arbitrary file read, including .env (security key, DB credentials) and the passwd file from non-sandboxed Twig template contexts, such as entry type title formats and URI formats.
The sandbox correctly blocks create() in system email templates, so this finding applies only to admin-configured, non-sandboxed contexts that require allowAdminChanges=true.
Prerequisites
- Admin access to the Craft control panel
allowAdminChangesmust betrue(default in dev/staging, recommendedfalsein production)- Admin must be able to edit entry type settings (title format, URI format)
- Any user who subsequently creates an entry in the affected section triggers the file read
Limitations
- Requires admin-level access: not exploitable by low-privilege users
allowAdminChangesmust betrue: production best practices recommendfalse, which prevents entry type configuration changes- Per Craft’s own severity guidelines, findings requiring
allowAdminChanges=trueare rated low - The
create()function is blocked by the Twig sandbox, so this cannot be exploited via system email templates or any other sandboxed context
Impact
An admin user (or an attacker who has compromised an admin account) can read arbitrary files from the server filesystem by setting a malicious entry type title format using create('SplFileObject', ['/path/to/file']). In production environments, this exposes .env files containing the CRAFT_SECURITY_KEY, database credentials, API keys, and other secrets. The file contents are rendered as entry titles visible to any user with permission to view entries in the affected section.
The impact is limited by the requirement for admin access and allowAdminChanges=true.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | craftcms/cms | ≥ 5.0.0-RC1&&< 5.10.6 | 5.10.6composer require craftcms/cms:^5.10.6 |
| 🐘Packagist | craftcms/cms | ≥ 4.0.0-RC1&&< 4.18.2 | 4.18.2composer require craftcms/cms:^4.18.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for craftcms/cms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update craftcms/cms to 5.10.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72779 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.
Frequently Asked Questions
Is CVE-2026-72779 in your dependencies?
Find it across Packagist, including transitive dependencies.