Cyber Resilience

CVE-2025-26900

CriticalRCE

Published: 25 February 2025

Published
25 February 2025
Modified
23 April 2026
KEV Added
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Patch
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CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0011 29.8th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-26900 is a critical-severity Deserialization of Untrusted Data (CWE-502) vulnerability. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 29.8th 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 RA-5 (Vulnerability Monitoring and Scanning) and SI-10 (Information Input Validation).

Deeper analysis

CVE-2025-26900 is a Deserialization of Untrusted Data vulnerability (CWE-502) in the flexmls Flexmls® IDX (flexmls-idx) WordPress plugin, enabling Object Injection. This issue affects all versions from n/a through 3.14.27.

The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating that unauthenticated attackers with network access can exploit it remotely with low complexity and no user interaction. Successful exploitation could result in high impacts to confidentiality, integrity, and availability.

The Patchstack advisory at https://patchstack.com/database/Wordpress/Plugin/flexmls-idx/vulnerability/wordpress-flexmls-idx-plugin-plugin-3-14-27-php-object-injection-vulnerability?_s_id=cve provides details on this PHP Object Injection vulnerability in the flexmls-idx plugin up to version 3.14.27. Security practitioners should consult the advisory for recommended mitigations.

EU & UK References

Vulnerability details

Deserialization of Untrusted Data vulnerability in flexmls Flexmls® IDX flexmls-idx allows Object Injection.This issue affects Flexmls® IDX: from n/a through <= 3.14.27.

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 →
Why these techniques?

Remote unauthenticated deserialization/object injection vulnerability in a public-facing WordPress plugin directly enables exploitation of public-facing applications.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2024-13770Shared CWE-502
CVE-2026-27303Shared CWE-502
CVE-2025-53586Shared CWE-502
CVE-2025-64353Shared CWE-502
CVE-2025-31047Shared CWE-502
CVE-2026-27096Shared CWE-502
CVE-2023-49886Shared CWE-502
CVE-2026-23542Shared CWE-502
CVE-2025-66631Shared CWE-502
CVE-2026-40044Shared CWE-502

Affected Assets

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-2 Flaw Remediation good match
prevent

Directly mitigates CVE-2025-26900 by remediating the deserialization flaw through patching the vulnerable flexmls-idx plugin versions up to 3.14.27.

SI-10 Information Input Validation good match
prevent

Prevents object injection by validating untrusted data inputs prior to deserialization processing in the flexmls-idx plugin.

RA-5 Vulnerability Monitoring and Scanning good match
detect

Identifies the deserialization vulnerability (CVE-2025-26900) in the flexmls-idx plugin through regular vulnerability scanning of the WordPress environment.

References