Cyber Posture

CVE-2026-25400

HighRCE

Published: 25 March 2026

Published
25 March 2026
Modified
24 April 2026
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0006 19.0th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-25400 is a high-severity Deserialization of Untrusted Data (CWE-502) vulnerability. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 19.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mitigates CVE-2026-25400 by requiring timely patching of the deserialization flaw in Apicona theme versions up to 24.1.0.

prevent

Prevents object injection from untrusted data deserialization in the Apicona PHP code by enforcing validation of all relevant inputs.

detectrespond

Identifies the vulnerable Apicona theme through vulnerability scanning, enabling detection and remediation of the deserialization flaw.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
Why these techniques?

PHP object injection (deserialization) in public-facing WordPress theme directly enables T1190 exploitation by low-privileged authenticated attackers over the network; resulting RCE maps to T1059.004 Unix Shell via gadget chains invoking system commands.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Deserialization of Untrusted Data vulnerability in thememount Apicona apicona allows Object Injection.This issue affects Apicona: from n/a through <= 24.1.0.

Deeper analysisAI

CVE-2026-25400 is a Deserialization of Untrusted Data vulnerability (CWE-502) in the Apicona WordPress theme by thememount, affecting all versions up to and including 24.1.0. The flaw enables Object Injection through untrusted data deserialization in PHP code.

With a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), the vulnerability can be exploited by an authenticated attacker possessing low privileges, such as a standard WordPress user. Exploitation occurs over the network with low complexity and requires no user interaction, allowing the attacker to achieve high impacts on confidentiality, integrity, and availability, potentially leading to remote code execution or full system compromise.

The Patchstack advisory provides further details on this PHP Object Injection vulnerability in the Apicona theme version 24.1.0, including recommended mitigations such as updating to a patched version where available.

Details

CWE(s)

CVEs Like This One

CVE-2026-25358Shared CWE-502
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CVE-2025-1913Shared CWE-502

References