CVE-2026-55573

CRITICAL 9.8

e107: Unsafe deserialization in install.php allows unauthenticated RCE via POP chain

CVSS Score

9.8

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-502
Vendor	e107inc
Product	e107
Published	Oct 14, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

e107inc / e107

< 2.3.7

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/e107inc/e107/security/advisories/GHSA-c8h6-wpj3-4cr8 github.com: https://github.com/e107inc/e107/commit/5d6d649e8cf01854d6024d07997c2449fdd75f24 github.com: https://github.com/e107inc/e107/commit/6c404295213952aedb9b3689be19dd4c7ba550b0 github.com: https://github.com/e107inc/e107/releases/tag/v2.3.7