CVE-2025-47547 is a vulnerability classified as CWE-79, which corresponds to Improper Neutralization of Input During Web Page Generation, commonly known as Cross-site Scripting (XSS). This specific vulnerability affects the SendPulse Email Marketing Newsletter product, versions up to and including 2.1.6. The flaw allows an attacker to inject malicious scripts that are stored persistently within the application, leading to Stored XSS attacks. Stored XSS occurs when malicious input is saved by the application and later rendered in web pages viewed by other users without proper sanitization or encoding. This can enable attackers to execute arbitrary JavaScript in the context of the victim's browser session, potentially leading to session hijacking, credential theft, unauthorized actions on behalf of the user, or distribution of malware. The CVSS v3.1 base score for this vulnerability is 6.5, indicating a medium severity level. The vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L indicates that the attack can be launched remotely over the network, requires low attack complexity, needs privileges (authenticated user), requires user interaction, and impacts confidentiality, integrity, and availability to a limited extent. The scope is changed, meaning the vulnerability affects resources beyond the initially vulnerable component. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was published on May 7, 2025, and has been enriched by CISA, indicating recognition by US cybersecurity authorities. The root cause is insufficient input validation or output encoding during web page generation, allowing malicious scripts to be embedded and executed in users' browsers.

For European organizations using SendPulse Email Marketing Newsletter, this vulnerability poses a significant risk to the confidentiality and integrity of their communications and user data. Attackers exploiting this Stored XSS flaw could hijack user sessions, steal sensitive information such as login credentials or personal data, and manipulate newsletter content to distribute malicious payloads or phishing links. This could damage the organization's reputation, lead to regulatory non-compliance (e.g., GDPR violations due to data breaches), and cause operational disruptions if attackers leverage the vulnerability to perform unauthorized actions. Since the vulnerability requires authenticated access and user interaction, internal users or subscribers could be targeted, increasing the risk of insider threats or social engineering attacks. The scope change in the CVSS vector suggests that exploitation could affect components beyond the immediate application, potentially impacting integrated systems or services. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once patches are released or if the vulnerability becomes public knowledge.

European organizations should prioritize the following specific mitigation steps: 1) Immediately audit and monitor all instances of SendPulse Email Marketing Newsletter for unusual activity or signs of exploitation, focusing on user-generated content and newsletter templates. 2) Restrict privileges to the minimum necessary for users interacting with the newsletter system to reduce the risk of exploitation by authenticated users. 3) Implement robust input validation and output encoding on all user-supplied data within the newsletter platform, especially for HTML and script content, to prevent injection of malicious code. 4) Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers accessing the newsletters. 5) Educate users and administrators about the risks of clicking on unexpected links or interacting with suspicious newsletter content. 6) Coordinate with SendPulse support or vendors to obtain patches or updates as soon as they become available and apply them promptly. 7) Consider isolating the newsletter platform from critical internal systems to contain potential impacts. 8) Conduct regular security assessments and penetration testing focused on web application vulnerabilities, including XSS, to identify and remediate similar issues proactively.