CVE-2026-85000 in EmbedPress Plugin
Summary
by MITRE • 10/15/2026
The EmbedPress WordPress plugin before 4.6.8 does not perform any capability or nonce check on an unauthenticated request that triggers a server-side, credential-bearing request to a third-party API and stores attacker-controlled cache entries, allowing unauthenticated attackers to consume the site owner's third-party API quota and write unbounded records into the site's database.
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Analysis
by VulDB Data Team • 10/15/2026
The vulnerability identified in EmbedPress versions prior to 4.6.8 represents a critical failure in access control mechanisms within a widely used WordPress plugin designed for embedding external media content. The core technical flaw lies in the absence of both capability checks and nonce verification on specific unauthenticated endpoints exposed by the plugin. In standard WordPress development practices, any action that modifies data or triggers significant server-side operations must validate that the requester is an authenticated user with appropriate administrative privileges and possesses a valid security token to prevent Cross-Site Request Forgery attacks. EmbedPress fails to implement these essential safeguards for requests intended to fetch and cache content from third-party APIs such as YouTube, Vimeo, or Instagram. This oversight allows any remote actor, without requiring authentication, to interact directly with the plugin's internal logic by sending crafted HTTP requests that mimic legitimate administrative actions.
The operational impact of this vulnerability is twofold, involving both resource exhaustion and data integrity compromise. First, because the unauthenticated request triggers a server-side call to an external API using the site owner's credentials or API keys stored within the WordPress configuration, attackers can force the victim website to consume its allocated third-party API quota at will. This constitutes a form of abuse where the attacker leverages the victim's resources for their own purposes, potentially leading to service degradation if the API provider throttles or suspends access due to excessive usage. Second, and more severely, the vulnerability allows attackers to write unbounded records into the site’s database. By manipulating the parameters sent in these requests, an attacker can inject arbitrary data that is subsequently cached by the plugin. This results in a denial of service through database bloat, where the continuous accumulation of malicious cache entries consumes disk space and degrades server performance, potentially rendering the website inaccessible to legitimate users.
From a classification perspective, this vulnerability aligns with CWE-284 Improper Access Control, as it stems from insufficient restrictions on unauthenticated actors performing sensitive operations. It also relates closely to CWE-798 Use of Hard-coded Credentials if the API keys are stored in plaintext or improperly secured within the database, although the primary issue is the lack of authorization checks rather than credential exposure per se. In terms of offensive security frameworks such as MITRE ATT&CK, this behavior corresponds to techniques involving resource hijacking and data injection via web application vulnerabilities. The ability to write unbounded records into the database also touches upon CWE-78 Improper Neutralization of Special Elements used in an OS Command or similar injection flaws if those cached entries are later rendered without proper sanitization, potentially leading to Stored Cross-Site Scripting (CWE-79) depending on how the plugin displays the cached content.
Mitigation for this vulnerability requires immediate action by site administrators and developers. The primary remediation is to upgrade EmbedPress to version 4.6.8 or later, where these access control checks have been implemented. For sites that cannot immediately update due to compatibility concerns with other plugins, temporary mitigations include restricting access to the WordPress admin area via IP whitelisting if feasible, although this may not fully prevent exploitation of API endpoints depending on how they are routed. Additionally, implementing a Web Application Firewall (WAF) can help detect and block anomalous request patterns associated with bulk caching operations or unusual spikes in outbound traffic to third-party APIs. Regular auditing of database size and monitoring for unexpected growth in cache tables can also serve as an early detection mechanism for ongoing exploitation attempts until the software is patched.