CVE-2025-5920 is a vulnerability identified in the Sharable Password Protected Posts plugin, specifically in versions prior to 1.1.1. This plugin allows users to create password-protected posts that can be shared via a secret key. The vulnerability arises because the secret key, which is intended to secure access to these posts, is transmitted as a GET parameter and is exposed through the REST API. This exposure constitutes a CWE-201 weakness, which involves the insertion of sensitive information into sent data. Essentially, the secret key can be retrieved by unauthorized parties through the REST API endpoint, bypassing the intended password protection mechanism. This flaw undermines the confidentiality of the protected content, as attackers or unauthorized users can gain access to sensitive posts without needing the password itself. The vulnerability does not require authentication or user interaction to be exploited, making it easier for attackers to leverage. Although no known exploits are currently reported in the wild, the risk remains significant due to the nature of the exposure. The lack of a CVSS score suggests that the vulnerability is newly published and has not yet been fully assessed for severity. The affected product is primarily used in WordPress environments, where password-protected posts are shared via secret keys embedded in URLs. The vulnerability is particularly critical because REST APIs are often accessible over the internet, increasing the attack surface. Without a patch available at the time of reporting, users of the affected versions remain vulnerable to unauthorized access to sensitive content.

For European organizations, this vulnerability poses a notable risk to the confidentiality of sensitive information shared internally or externally via password-protected posts. Organizations that use the Sharable Password Protected Posts plugin to share confidential documents, announcements, or other sensitive content could inadvertently expose this data to unauthorized parties. This could lead to data breaches, loss of intellectual property, or leakage of personally identifiable information (PII), potentially violating GDPR and other data protection regulations. The exposure of secret keys via the REST API could also facilitate further attacks, such as phishing or social engineering, by revealing the existence of sensitive content. Since the vulnerability does not require authentication, it increases the risk of automated scanning and exploitation by malicious actors. The impact extends to reputational damage and potential regulatory fines for organizations failing to protect sensitive data adequately. Given the widespread use of WordPress in Europe, especially among SMEs and public sector entities, the vulnerability could affect a broad range of organizations that rely on this plugin for secure content sharing.

Immediate mitigation steps include disabling the Sharable Password Protected Posts plugin until a patched version (1.1.1 or later) is released and applied. Organizations should audit their WordPress installations to identify the presence of this plugin and verify the version in use. If disabling the plugin is not feasible, restricting REST API access through web application firewalls (WAFs) or server-level controls to trusted IP addresses can reduce exposure. Additionally, monitoring REST API logs for unusual access patterns or requests containing secret keys can help detect potential exploitation attempts. Organizations should also review and rotate any secret keys or passwords that may have been exposed. As a longer-term measure, developers should update the plugin to avoid transmitting sensitive keys in GET parameters and ensure that REST API endpoints do not expose sensitive information without proper authentication and authorization checks. Implementing strict access controls and employing security headers to limit API exposure are recommended. Finally, organizations should educate users about the risks of sharing sensitive URLs and encourage the use of more secure content sharing methods where possible.