CVE-2026-1217 in Duplicate Post Plugin
Summary
by MITRE • 03/18/2026
The Yoast Duplicate Post plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the clone_bulk_action_handler() and republish_request() functions in all versions up to, and including, 4.5. This makes it possible for authenticated attackers, with Contributor-level access and above, to duplicate any post on the site including private, draft, and trashed posts they shouldn't have access to. Additionally, attackers with Author-level access and above can use the Rewrite & Republish feature to overwrite any published post with their own content.
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Analysis
by VulDB Data Team • 03/22/2026
The vulnerability identified as CVE-2026-1217 affects the Yoast Duplicate Post plugin for WordPress, representing a critical authorization flaw that undermines the platform's content management security model. This issue stems from insufficient capability checks within two core functions: clone_bulk_action_handler() and republish_request(). The flaw exists across all versions up to and including 4.5, making it a widespread concern for WordPress installations that rely on this popular plugin for content duplication and republishing functionality. The vulnerability specifically targets the permission system that should normally restrict users based on their roles and capabilities within the WordPress ecosystem.
The technical implementation of this vulnerability allows authenticated attackers who possess Contributor-level access or higher to exploit the missing capability checks and duplicate posts that they should not normally be able to access. This includes private posts, draft content, and posts in the trash that are typically restricted to administrators or editors. The flaw essentially bypasses WordPress's inherent access control mechanisms by failing to verify whether the requesting user has proper authorization to perform these actions on the target content. The clone_bulk_action_handler() function appears to process bulk duplication requests without validating user permissions against the specific post types or statuses, while the republish_request() function similarly lacks adequate capability verification for the rewrite and republish operations.
The operational impact of this vulnerability extends beyond simple content duplication, as it enables attackers with Author-level privileges or higher to overwrite any published content with their own material. This represents a significant threat to content integrity and potentially allows for malicious content injection, defacement, or the propagation of false information. The vulnerability particularly affects sites where multiple authors contribute content, as it creates a scenario where less privileged users can manipulate content that should be restricted to higher-level administrators. This capability can be exploited for various malicious purposes including the creation of false news articles, the injection of malware through content modification, or the disruption of legitimate content workflows. The attack vector is particularly concerning because it leverages legitimate plugin functionality to perform unauthorized actions, making detection more difficult.
Security practitioners should prioritize immediate remediation of this vulnerability by updating the Yoast Duplicate Post plugin to a version that includes proper capability checks and access controls. The fix should implement comprehensive permission verification that aligns with WordPress's standard capability hierarchy and ensures that users can only perform actions appropriate to their roles. Organizations should also conduct thorough audits of their WordPress installations to identify any other plugins that may suffer from similar authorization flaws, as this represents a common pattern in WordPress plugin development where access control mechanisms are insufficiently implemented. The vulnerability demonstrates the critical importance of capability checks in web applications and aligns with CWE-284, which addresses improper access control, and may map to ATT&CK techniques related to privilege escalation and content injection.