CVE-2026-39390

CVE-2026-39390 is a medium-severity vulnerability in Ci4-cms-erp Ci4ms with a CVSS 3.x base score of 5.5. 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-79.

Key facts

Description

CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. Prior to 0.31.4.0, the Google Maps iframe setting (cMap field) in compInfosPost() sanitizes input using strip_tags() with an <iframe> allowlist and regex-based removal of on\w+ event handlers. However, the srcdoc attribute is not an event handler and passes all filters. An attacker with admin settings access can inject an <iframe srcdoc="..."> payload with HTML-entity-encoded JavaScript that executes in the context of the parent page when rendered to unauthenticated frontend visitors. This vulnerability is fixed in 0.31.4.0.

Frequently asked questions

What is CVE-2026-39390?
CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. Prior to 0.31.4.0, the Google Maps iframe setting (cMap field) in compInfosPost() sanitizes input using strip_tags() with an <iframe> allowlist and regex-based removal of on\w+ event handlers. However, the srcdoc attribute is not an event handler and passes all filters. An attacker with admin settings access can inject an <iframe srcdoc="..."> payload with HTML-entity-encoded JavaScript that executes in the context of the parent page when rendered to unauthenticated frontend visitors. This vulnerability is fixed in 0.31.4.0.
How severe is CVE-2026-39390?
CVE-2026-39390 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-39390 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-39390?
CVE-2026-39390 affects Ci4-cms-erp Ci4ms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-39390?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-39390 have an EU (EUVD) identifier?
Yes. CVE-2026-39390 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20483.
When was CVE-2026-39390 published?
CVE-2026-39390 was published on 2026-04-08 and last updated on 2026-06-17.

References

Affected products (1)

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