CVE-2026-55573
e107: Unsafe deserialization in install.php allows unauthenticated RCE via POP chain
Description
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.
INFO
Published Date :
Oct. 14, 2026, 6:17 p.m.
Last Modified :
Oct. 16, 2026, 8:04 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update e107 CMS to version 2.3.7.
- Remove or secure install.php after installation.
- Verify that bundled GuzzleHttp classes are restricted.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-55573.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-55573 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-55573
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-55573 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-55573 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 15, 2026
Action Type Old Value New Value Added Reference https://github.com/e107inc/e107/security/advisories/GHSA-c8h6-wpj3-4cr8 Added SSVC {'id': 'CVE-2026-55573', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-15T15:00:08.038362Z'} -
New CVE Received by [email protected]
Oct. 14, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-502 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/55xxx/CVE-2026-55573.json">CVE-2026-55573</a> Added Reference https://github.com/e107inc/e107/commit/5d6d649e8cf01854d6024d07997c2449fdd75f24 Added Reference https://github.com/e107inc/e107/commit/6c404295213952aedb9b3689be19dd4c7ba550b0 Added Reference https://github.com/e107inc/e107/releases/tag/v2.3.7 Added Reference https://github.com/e107inc/e107/security/advisories/GHSA-c8h6-wpj3-4cr8