CVE-2026-28784 — craftcms/cms
Fix: craftcms/cms#18208CVE-2026-28784 is a CWE-1336 vulnerability in craftcms/cms. A fix is available for craftcms/cms — see the affected versions and patch details below.
Craft is affected by potential authenticated Remote Code Execution via Twig SSTI
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-2026-28784.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
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
Craft is a content management system (CMS). Prior to 5.8.22 and 4.16.18, it is possible to craft a malicious payload using the Twig map filter in text fields that accept Twig input under Settings in the Craft control panel or using the System Messages utility, which could lead to a RCE. For this to work, you must have administrator access to the Craft Control Panel, and allowAdminChanges must be enabled for this to work, which is against our recommendations for any non-dev environment. Alternatively, you can have a non-administrator account with allowAdminChanges disabled, but you have access to the System Messages utility. Users should update to the patched versions (5.8.22 and 4.16.18) to mitigate the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | craftcms/cms | ≥ 5.0.0-RC1&&< 5.9.0-beta.1 | 5.9.0-beta.1composer require craftcms/cms:^5.9.0-beta.1 |
| 🐘Packagist | craftcms/cms | ≥ 4.0.0-RC1&&< 4.17.0-beta.1 | 4.17.0-beta.1composer require craftcms/cms:^4.17.0-beta.1 |
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 5.9.0-beta.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-28784 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-28784 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-28784. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-28784 in your dependencies?
O3 Security finds CVE-2026-28784 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.