CVE-2026-119160 in Smart Post Plugin
Summary
by MITRE • 10/31/2026
The Smart Post – Post Grid, Post Carousel, Post Slider Gutenberg Blocks for Blog & News plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'display_name' parameter in all versions up to, and including, 4.0.9 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires the victim page to contain an Author Filter block alongside a grid or live-filter block, and execution is triggered by a visitor clicking the attacker's author entry in the dropdown — a standard filter interaction requiring no elevated privileges from the victim.
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Analysis
by VulDB Data Team • 10/31/2026
The Smart Post plugin for WordPress, specifically versions up through 4.0.9, contains a critical security flaw classified as Stored Cross-Site Scripting within its Gutenberg block architecture. This vulnerability stems directly from insufficient input sanitization and output escaping mechanisms applied to the display_name parameter used in post grid, carousel, and slider blocks. Because the application fails to properly validate or encode user-supplied data before storing it in the database and subsequently rendering it on public-facing pages, malicious actors can persistently inject executable JavaScript code into the site's content structure. This lack of rigorous data handling is a fundamental design oversight that transforms standard administrative inputs into vectors for client-side attacks, undermining the integrity of the web application environment.
The operational impact of this vulnerability allows authenticated attackers with subscriber-level access or higher to execute arbitrary scripts in the context of any user who views the compromised page. The exploitation chain relies on specific block configurations; specifically, the victim's page must include an Author Filter block alongside a grid or live-filter block created by the Smart Post plugin. When such a configuration is present, the attacker injects malicious script payloads into their own author profile name via the display_name field. This payload remains dormant until interaction occurs, at which point it becomes active within the browser environment of any visitor accessing that page.
The trigger mechanism for this attack is particularly insidious because it requires no elevated privileges from the victim user and does not rely on social engineering tactics such as phishing links or deceptive prompts. Instead, execution is initiated by a standard filter interaction where a site visitor clicks on the attacker's author entry within the dropdown menu provided by the Author Filter block. This action causes the browser to parse and execute the injected JavaScript code immediately. Consequently, attackers can steal session cookies, hijack user sessions, deface websites, or redirect users to malicious external sites without the victim realizing they have been compromised until significant damage has occurred.
From a classification perspective, this vulnerability aligns with CWE-79 Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting and specifically falls under Stored XSS where the payload is saved on the target server rather than being reflected in an immediate request. In terms of adversary tactics, this behavior maps to ATT&CK technique T1059 Command and Scripting Interpreter for executing code within a victim's browser context and potentially T1204 User Execution if further social engineering were employed after initial access. The persistence aspect also relates to the ability to maintain foothold through stored payloads that remain active until manually removed from the database or plugin settings.
Mitigation strategies must prioritize immediate remediation of the codebase alongside broader security hygiene practices. Administrators should update the Smart Post plugin to version 4.0.10 or later where these sanitization and escaping issues have been addressed by the developers. Until an official patch is available, site owners can implement temporary mitigations such as restricting author filter visibility to logged-in users with higher privileges if feasible, although this may impact user experience. Additionally, deploying a Web Application Firewall capable of detecting and blocking XSS payloads in POST requests and response bodies can provide a layer of defense against exploitation attempts. Regular security audits focusing on input validation and output encoding across all custom plugins are essential to prevent similar vulnerabilities from being introduced into the WordPress ecosystem.