CVE-2025-31423 CRITICAL

CVE-2025-31423: WordPress Umberto theme <= 1.2.8 - PHP Object Injection Vulnerability

Vendor Ancorathemes

Product Umberto

Weakness CWE-502 · Unsafe deserialization

Published May 23, 2025

Last update April 28, 2026

View on NVD All CVEs

CVSS base score

9.8/10

Attack vector Network

Attack complexity Low

Privileges required None

User interaction None

Confidentiality High

Integrity High

CVSS vector

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

What the vulnerability does

01Description

Deserialization of Untrusted Data vulnerability in AncoraThemes Umberto umberto allows Object Injection.This issue affects Umberto: from n/a through <= 1.2.8.

Explanation of Vulnerability in Simple Terms

02Summary

Umberto versions up to 1.2.8 contain a deserialization vulnerability that allows unauthenticated attackers to run arbitrary code on the site without user interaction. The vulnerability exists in how the product processes untrusted serialized data. An attacker can exploit this remotely over the network to gain full control of the affected installation.

What an attacker can do

03Attacker Capabilities

Run arbitrary code on the site and take complete control of it.

Potential impact on your site

04Site Impact

Complete compromise of the site, including data theft, malware injection, and site defacement.

Conditions required to exploit

05Prerequisites

Network access only; no authentication or user interaction required.

Key dates

06Disclosure timeline

May 23, 2025 CVE published

April 28, 2026 Record updated

External resources

07References

NVD — National Vulnerability Database https://nvd.nist.gov/vuln/detail/CVE-2025-31423 CWE — Common Weakness Enumeration https://cwe.mitre.org/data/definitions/502.html AskarLabs — CWE-502 write-up Deserialization of Untrusted Data

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