CVE-2026-1298 is a vulnerability classified under CWE-862 (Missing Authorization) affecting the Easy Replace Image plugin for WordPress, versions up to and including 3.5.2. The root cause is the absence of proper capability checks in the `image_replacement_from_url` function, which is hooked to the `eri_from_url` AJAX action. This flaw allows any authenticated user with Contributor-level permissions or higher to invoke this AJAX action and replace arbitrary image attachments on the WordPress site with images sourced from external URLs. Because Contributors typically cannot upload files or modify existing media, this vulnerability escalates their ability to manipulate site content indirectly. The impact includes potential site defacement, insertion of malicious or phishing images, and general content integrity compromise. The CVSS v3.1 score is 5.3 (medium), reflecting that the attack vector is network-based, requires no user interaction, and no elevated privileges beyond Contributor access. The vulnerability does not affect confidentiality or availability but compromises integrity. No patches or official fixes are currently linked, and no known exploits have been reported in the wild as of the publication date. The vulnerability is particularly relevant for WordPress sites using this plugin, which is popular for image management and replacement tasks.

For European organizations, this vulnerability poses a moderate risk primarily to the integrity of their web content. Attackers with Contributor access can replace images with malicious or misleading content, potentially damaging brand reputation, enabling phishing campaigns, or misleading site visitors. While it does not directly expose sensitive data or disrupt service availability, the ability to manipulate visible content can have serious consequences, especially for e-commerce, news, governmental, or financial websites where trust and accurate information are critical. Organizations relying on WordPress with this plugin should be aware that attackers do not need administrator privileges, lowering the barrier to exploitation. The reputational damage and potential for social engineering attacks could lead to financial losses and regulatory scrutiny under European data protection and consumer protection laws.

Immediate mitigation steps include restricting Contributor-level user permissions and auditing existing user roles to ensure minimal necessary access. Site administrators should disable or remove the Easy Replace Image plugin until an official patch is released. If removal is not feasible, implementing web application firewall (WAF) rules to block or monitor AJAX requests to the `eri_from_url` action can reduce risk. Monitoring logs for unusual image replacement activity is recommended. Additionally, organizations should enforce multi-factor authentication (MFA) for all authenticated users to reduce the risk of compromised accounts being used to exploit this vulnerability. Regular backups of media libraries and site content will facilitate recovery if defacement occurs. Finally, staying updated with vendor advisories and applying patches promptly once available is critical.