Craft CMS’ save_images_Asset GraphQL mutation can be abused to fetch internal URLs by providing a domain that resolves to an internal IP address, bypassing hostname validation. When a non‑image file extension such as .txt is allowed, downstream image validation is skipped, enabling an attacker with permission to the mutation to retrieve sensitive data like AWS instance metadata credentials from the underlying host. This flaw represents a Server‑Side Request Forgery weakness and can lead to credential leakage.

Versions 3.5.0 through 4.16.17 and 5.0.0‑RC1 through 5.8.21 of Craft CMS are affected. The issue is fixed in 4.16.18 and 5.8.22 and later releases.

The CVSS score of 5.3 indicates medium severity, while an EPSS score below 1% shows a very low exploitation probability. The vulnerability is not listed in CISA’s KEV catalog. Exploitation requires an authenticated user with the ability to invoke the save_images_Asset mutation and supply a domain that resolves to an internal IP. Once executed, the attacker can exfiltrate AWS metadata credentials, representing a serious confidentiality breach if privileged accounts are targeted or compromised.