CVE-2026-39391 | CI4MS has Stored XSS via Unescaped Blacklist Note in Admin User List

Exp

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 blacklist (ban) note parameter in UserController::ajax_blackList_post() is stored in the database without sanitization and rendered into an HTML data-note attribute without escaping. An admin with blacklist privileges can inject arbitrary JavaScript that executes in the browser of any other admin who views the user management page. This vulnerability is fixed in 0.31.4.0.

Published: 2026-04-08 Last update: 2026-04-16 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-39391 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-39391

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-39391

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-09 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-39391

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 1.7 2.7 [email protected]

Weakness enumeration for CVE-2026-39391

GitHub Security Advisory for CVE-2026-39391

GHSA-7cm9-v848-cfh2 · Severity: medium · Ecosystem: composer — CI4MS has stored XSS via Unescaped Blacklist Note in Admin User List

Affected software / configurations for CVE-2026-39391

Vendor Product Version Raw CPE
ci4-cms-erp ci4ms < 0.31.4.0 cpe:2.3:a:ci4-cms-erp:ci4ms:*:*:*:*:*:*:*:*

References for CVE-2026-39391

cvelogic Threat Intelligence