CVE-2026-55792

CVE-2026-55792 is a medium-severity vulnerability with a CVSS 4.0 base score of 6.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

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 Craft’s 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 Craft’s 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.

Frequently asked questions

What is CVE-2026-55792?
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 Craft’s 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 Craft’s 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.
How severe is CVE-2026-55792?
CVE-2026-55792 has a CVSS 4.0 base score of 6.0, rated medium severity.
Is CVE-2026-55792 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-55792?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-55792 published?
CVE-2026-55792 was published on 2026-07-02.

References

Other CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) vulnerabilities

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