CVE-2025-49048 is a medium-severity vulnerability classified under 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 Inspectlet User Session Recording and Heatmaps product, versions up to 2.0. The vulnerability is a Stored XSS, meaning that malicious input is persistently stored by the application and later rendered in web pages without proper sanitization or encoding. This allows an attacker to inject malicious scripts that execute in the context of other users' browsers when they view the affected pages. The CVSS 3.1 vector (AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L) indicates that the attack can be performed remotely over the network with low attack complexity but requires high privileges and user interaction. The scope is changed, meaning the vulnerability affects components beyond the initially vulnerable component. The impact includes limited confidentiality, integrity, and availability losses, such as theft of session tokens, defacement, or disruption of service. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was reserved in May 2025 and published in August 2025, indicating it is a recent discovery. Inspectlet is a web analytics tool used for session recording and heatmaps, which means it is integrated into websites to monitor user behavior. The vulnerability could allow attackers to compromise the security of websites using Inspectlet by injecting malicious scripts that affect site visitors or administrators.

For European organizations, the impact of this Stored XSS vulnerability can be significant, especially for those relying on Inspectlet for user behavior analytics. Exploitation could lead to session hijacking, unauthorized actions performed on behalf of users, or the injection of malicious content that damages brand reputation and user trust. Since Inspectlet is embedded in client websites, the attack surface includes any European company using this tool, potentially exposing their customers and internal users to attacks. This could lead to breaches of personal data under GDPR, resulting in regulatory penalties and loss of customer confidence. Additionally, the vulnerability could be leveraged as a foothold for further attacks within the organization's network or to spread malware. The requirement for high privileges and user interaction somewhat limits exploitation but does not eliminate risk, especially in environments where privileged users may be targeted via social engineering. The scope change indicates that the vulnerability could affect multiple components or users beyond the initially targeted system, increasing potential damage.

1. Immediate mitigation should include disabling or removing the Inspectlet integration from critical web properties until a patch is available. 2. Monitor and restrict privileged user access to the Inspectlet management interfaces, enforcing strict authentication and authorization controls. 3. Implement Content Security Policy (CSP) headers to limit the execution of unauthorized scripts and reduce the impact of XSS attacks. 4. Sanitize and validate all inputs and outputs related to Inspectlet data, especially any user-generated content or parameters that may be reflected in the web pages. 5. Conduct regular security assessments and penetration tests focusing on XSS vulnerabilities in web analytics tools and third-party integrations. 6. Stay updated with vendor advisories for patches or updates addressing this vulnerability and apply them promptly once available. 7. Educate privileged users about the risks of social engineering and the importance of cautious interaction with suspicious links or content. 8. Use web application firewalls (WAF) with rules tuned to detect and block XSS payloads targeting Inspectlet components.