CVE-2026-55792
Description
Craft CMS is a content management system (CMS). In versions starting from 4.0.0-RC1 and prior to 4.18.0, and 5.0.0-RC1 and above, prior to 5.10.0, the dataUrl() Twig function is included in Craftβs Twig sandbox allowlist, allowing any control panel user granted the utility:system-messages permission to embed a file-reading payload into system email templates. When those emails are sent, the server reads the target file and returns its contents as a base64-encoded data URL embedded in the email body. The .env file, which typically contains the database password, CRAFT_SECURITY_KEY, and third-party API keys, passes all of Craftβs existing dataUrl() protection checks and is fully exfiltrated. Obtaining CRAFT_SECURITY_KEY enables an attacker to forge session tokens and escalate to full admin account takeover. This issue has been fixed in versions 4.18.0 and 5.10.0.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or β if you've already worked around this in production β publish your fix to the community-verified tier.
β Propose a mitigation on Community β Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
CWEs
CWE-200
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.