---
id: CVE-2026-55573
title: e107 is a content management system (CMS)
summary: >-
  e107 is a content management system (CMS). Prior to 2.3.7, install.php decodes
  the attacker-controlled previous_steps POST parameter and passes it to
  unserialize() at file scope and again in the e_install constructor without
  restricting …
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-502
published: '2026-10-14'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T18:17:38.013'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55573'
references:
  - url: >-
      https://github.com/e107inc/e107/commit/5d6d649e8cf01854d6024d07997c2449fdd75f24
    label: security-advisories@github.com
  - url: >-
      https://github.com/e107inc/e107/commit/6c404295213952aedb9b3689be19dd4c7ba550b0
    label: security-advisories@github.com
  - url: 'https://github.com/e107inc/e107/releases/tag/v2.3.7'
    label: security-advisories@github.com
  - url: 'https://github.com/e107inc/e107/security/advisories/GHSA-c8h6-wpj3-4cr8'
    label: security-advisories@github.com
tags:
  - nvd
ingestedAt: '2026-10-14T18:47:39.315Z'
---

## Overview

e107 is a content management system (CMS). Prior to 2.3.7, install.php decodes the attacker-controlled previous_steps POST parameter and passes it to unserialize() at file scope and again in the e_install constructor without restricting allowed classes. The installer remains accessible after a normal installation, and a crafted object graph using the bundled GuzzleHttp\Psr7\PumpStream class can flow through paths.hash into site_path, where string coercion invokes an attacker-controlled callable. An unauthenticated attacker who can reach install.php can therefore execute arbitrary PHP functions with the web server process's privileges, leading to full server compromise. This issue is fixed in version 2.3.7.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.