CVE-2026-72779 Craft CMS 5.0.0-RC1 before 5.10.6 Arbitrary File Read via SplFileObject
Authenticated administrators can read arbitrary server files, including credentials, by exploiting a blocklist bypass in Twig template instantiation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72779?
CVE-2026-72779 is a high-severity path traversal vulnerability in craftcms cms, published on 11 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Craft CMS 5.0.0-RC1 before 5.10.6 and 4.0.0-RC1 before 4.18.2 contain an arbitrary file read vulnerability. The create() Twig function restricts class instantiation using a 5-entry blocklist that does not include SplFileObject, allowing an authenticated administrator (with allowAdminChanges=true) to configure a malicious entry type title or URI format that instantiates SplFileObject in a non-sandboxed template context. When a user subsequently creates an entry in the affected section, arbitrary files on the server (such as .env containing the security key and database credentials) are read and rendered as entry titles.
Weakness: CWE-184
Which versions are affected by CVE-2026-72779?
4 open source packages ship an affected version, including craftcms/cms.
| Package | Affected | Fixed in |
|---|---|---|
craftcms/cms Packagist | From 4.0.0-RC1 | 4.18.2 |
craftcms/cms Packagist | From 4.0.0-RC1 | 4.18.2 |
craftcms/cms Packagist | From 5.0.0-RC1 | 5.10.6 |
craftcms/cms Packagist | From 5.0.0-RC1 | 5.10.6 |
How do I fix CVE-2026-72779?
Upgrade craftcms/cms to a fixed version for your release line: 4.18.2 or 5.10.6.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-72779 being exploited?
There is no known exploitation of CVE-2026-72779 in the wild and no public exploit code.
Sources
Also known as GHSA-957r-qf9p-67xw.