CVE-2026-25400

HighRCE

Published: 25 March 2026

Published

25 March 2026

Modified

24 April 2026

KEV Added

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Patch

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CVSS Score v3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0034 26.2th percentile

Risk Priority 55 floored blend · peak EPSS

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 26.2th 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).

Deeper analysis

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.

OWASP Top 10 for Web (2025)

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-15713

Vulnerability details

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

CWE(s): CWE-502

Related Threats

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.

attack.mitre.org →

T1059.004 Unix Shell Execution

Adversaries may abuse Unix shell commands and scripts for execution.

attack.mitre.org →

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 v19.0