CVE-2025-49963 is a Reflected Cross-site Scripting (XSS) vulnerability identified in the growniche Simple Stripe Checkout plugin, a tool used to facilitate Stripe payment processing on websites. The vulnerability stems from improper neutralization of user-supplied input during the generation of web pages, which allows attackers to inject malicious JavaScript code that is reflected back to the user without adequate sanitization. This flaw affects all versions of the plugin up to and including 1.1.28. An attacker can exploit this vulnerability by crafting a malicious URL containing a payload that, when visited by a victim, executes arbitrary scripts in the victim’s browser context. This can lead to theft of session cookies, redirection to malicious sites, or unauthorized actions performed on behalf of the user. The vulnerability does not require authentication, increasing its risk profile, and does not currently have any known public exploits. The absence of a CVSS score necessitates a severity assessment based on impact and exploitability factors. The plugin is commonly used in e-commerce environments, making the vulnerability particularly relevant to organizations handling online payments. The technical details indicate the issue was reserved in June 2025 and published in October 2025, with no patch links currently available, suggesting that remediation is pending or in progress.

For European organizations, especially those operating e-commerce platforms or online payment services using the Simple Stripe Checkout plugin, this vulnerability poses a significant risk. Successful exploitation can compromise the confidentiality of user data, including session tokens and potentially sensitive payment information, leading to account takeover or fraudulent transactions. The integrity of the web application is also at risk, as attackers can manipulate the user experience or inject misleading content. Availability impact is generally low for XSS but could be indirectly affected if attackers use the vulnerability to launch further attacks or cause reputational damage. Given the widespread use of Stripe and WordPress-based plugins in Europe, the potential for targeted phishing campaigns leveraging this vulnerability is high. This could erode customer trust and lead to regulatory scrutiny under GDPR if personal data is compromised. The lack of authentication requirements and ease of exploitation increase the threat level, making it a priority for organizations to address promptly.

Organizations should immediately inventory their web assets to identify any use of the growniche Simple Stripe Checkout plugin and verify the version in use. Until an official patch is released, implement strict input validation and output encoding on all user-supplied data to prevent script injection. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts. Monitor web server logs for unusual URL parameters or repeated access attempts with suspicious payloads. Educate users and staff about the risks of clicking on untrusted links, especially those related to payment processing pages. Consider temporarily disabling the plugin or replacing it with alternative payment solutions if patching is delayed. Engage with the vendor or community for updates and apply patches as soon as they become available. Additionally, implement web application firewalls (WAFs) with rules designed to detect and block reflected XSS attempts targeting this plugin.