MCMS CVE-2026-88416

Exploitation requires reaching the MCMS 'custom model/form import' feature (versions 6.1.1 through 6.2.1) and supplying import data containing injected SQL that is processed by a vulnerable backend query. Although the published CVSS vector states PR:N (unauthenticated), the import capability is an administrative/backend function in MCMS, so in practice an attacker most likely needs access to that import workflow - authentication requirements are not confirmed from available data and should be verified against the vendor. Limiting factors: affected only in the 6.1.1-6.2.1 range, dependent on the import endpoint being exposed/reachable, and no evidence of exploitation against default internet-facing deployments.

The input CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N) scores this 9.8 Critical, implying remote unauthenticated SQL injection with full confidentiality, integrity and availability impact (CWE-89). However, this high score conflicts with the described attack surface: the flaw is in the 'custom model/form import' feature, which in MCMS is a backend/administrative function that normally requires an authenticated session - so PR:N is questionable and should be verified with the vendor. The EPSS score is low (0.19%, 9th percentile), indicating no statistically significant observed exploitation activity, and the CVE is NOT listed in CISA KEV, so there is no evidence of active exploitation. SSVC-style reading: exploitation status is 'none/public report only', automatable is unclear (likely limited because an authenticated/backend endpoint must be reached), and technical impact is total (full DB CIA via SQLi). Net: a genuinely serious SQLi worth patching, but the combination of low EPSS, no KEV, a niche product, and a probable authentication prerequisite argues this is NOT a top-of-queue internet-wide emergency - treat as high-priority for MCMS operators specifically rather than a mass-exploitation event. The PR:N claim versus a backend import feature is the key signal to reconcile before trusting the 9.8.

An attacker who can reach the MCMS custom model/form import function submits a crafted import payload containing malicious SQL, which is concatenated unsafely into a backend query, allowing extraction of credentials and content from the database or modification of data. The single public reference is a third-party GitHub issue writeup that may include reproduction details, but no confirmed public exploit tool was identified; realistic exploitation likely presupposes access to the import endpoint rather than a fully anonymous external request.