---
title: "CVE-2026-34558: CI4MS: Methods Management Full Account Takeover for All-Roles & Privilege-Escalation via Stored DOM XSS"
url: https://erroneo.us/security/cve/CVE-2026-34558/
description: "CVE-2026-34558 (ci4-cms-erp/ci4ms (Composer (PHP))): CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-03-30
date_modified: 2026-04-01
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-34558"
kev: false
cvss: 9.1
epss: 0.0038
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-34558: CI4MS: Methods Management Full Account Takeover for All-Roles & Privilege-Escalation via Stored DOM XSS

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.4% , percentile 31: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 31% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes ci4-cms-erp/ci4ms (Composer (PHP)) <= 0.28.6.0, fixed in 0.31.0.0 . Check your lockfile, including transitive dependencies.

## What it is

CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. Prior to version 0.31.0.0, the application fails to properly sanitize user-controlled input within the Methods Management functionality when creating or managing application methods/pages. Multiple input fields accept attacker-controlled JavaScript payloads that are stored server-side without sanitization or output encoding. These stored values are later rendered directly into administrative interfaces and global navigation components without proper encoding, resulting in Stored DOM-Based Cross-Site Scripting (XSS). This issue has been patched in version 0.31.0.0.

## Affected packages

- Composer (PHP) `ci4-cms-erp/ci4ms` <= 0.28.6.0 → fixed: 0.31.0.0

## Affected products (CVE record)

- ci4-cms-erp ci4ms: < 0.31.0.0

## Severity

- GitHub_M CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L`
- GitHub CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact partial .
- FIRST EPSS (model of 2026-10-21): 0.38% probability of exploitation activity in the next 30 days; percentile 31.

## Sources

- [GitHub Advisory GHSA-v77r-xg3p-75g7](https://github.com/advisories/GHSA-v77r-xg3p-75g7)
- [CVE.org record CVE-2026-34558](https://www.cve.org/CVERecord?id=CVE-2026-34558)
- [NVD entry CVE-2026-34558](https://nvd.nist.gov/vuln/detail/CVE-2026-34558)
- [github.com](https://github.com/ci4-cms-erp/ci4ms/security/advisories/GHSA-v77r-xg3p-75g7)

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Source page: https://erroneo.us/security/cve/CVE-2026-34558/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt