CVE-2026-3017
Published: 14 April 2026
Summary
CVE-2026-3017 is a high-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Wordpress (inferred from references). Its CVSS base score is 7.2 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 15.1th 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-2026-3017 is a PHP Object Injection vulnerability (CWE-502) affecting the Smart Post Show – Post Grid, Post Carousel & Slider, and List Category Posts plugin for WordPress in all versions up to and including 3.0.12. The flaw stems from deserialization of untrusted input within the import_shortcodes() function, enabling the injection of a PHP Object. Published on 2026-04-14, it carries a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H).
Authenticated attackers possessing Administrator-level access or higher can exploit this vulnerability to inject a PHP Object. The plugin itself contains no known POP chain, rendering it ineffective in isolation. However, if another plugin or theme on the target site provides a POP chain, exploitation could lead to actions such as deleting arbitrary files, retrieving sensitive data, or executing arbitrary code, depending on the chain's capabilities.
Mitigation is addressed in the plugin's WordPress repository via changeset 3490703 at https://plugins.trac.wordpress.org/changeset/3490703/post-carousel. Further details on the vulnerability and remediation are provided in the Wordfence threat intelligence advisory at https://www.wordfence.com/threat-intel/vulnerabilities/id/45690747-0b8d-4e2e-8dd0-07c12791c064?source=cve.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-22221
Vulnerability details
The Smart Post Show – Post Grid, Post Carousel & Slider, and List Category Posts plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.0.12 via deserialization of untrusted input in the import_shortcodes()…
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function. This makes it possible for authenticated attackers, with Administrator-level access and above, to inject a PHP Object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
PHP object injection in public-facing WordPress plugin enables admin-authenticated exploitation for RCE (via external POP chains), Unix shell command execution, and arbitrary file deletion.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly remediates the PHP object injection vulnerability by requiring identification, reporting, and patching of the deserialization flaw in the import_shortcodes() function.
Prevents object injection by enforcing validation of untrusted inputs prior to deserialization in the vulnerable plugin function.
Reduces exploitation risk by restricting user installation of vulnerable plugins or themes that could provide POP chains necessary for impact.