CVE-2025-44595 is a Cross Site Scripting (XSS) vulnerability affecting Halo version 2.20.17 and earlier. The vulnerability exists in the /halo_host/archives/{name} endpoint, where user-supplied input in the {name} parameter is not properly sanitized or encoded before being reflected in the web page output. This allows an attacker to inject malicious scripts that execute in the context of the victim's browser when they visit the affected URL. The vulnerability is classified under CWE-79, which corresponds to improper neutralization of input during web page generation. According to the CVSS v3.1 vector (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N), the attack can be performed remotely over the network without privileges, but requires user interaction (clicking a crafted link). The scope is changed (S:C), meaning the vulnerability can affect resources beyond the initially vulnerable component. The impact includes limited confidentiality and integrity loss, such as theft of session cookies, user impersonation, or manipulation of displayed content. Availability is not affected. No known exploits are currently reported in the wild, and no patches or fixes have been linked yet. The vulnerability was reserved in April 2025 and published in September 2025, indicating recent discovery. The lack of affected version details beyond "n/a" suggests incomplete disclosure or that all versions up to 2.20.17 are vulnerable. Overall, this vulnerability represents a medium-severity risk typical of reflected XSS issues in web applications that handle user input insecurely.

For European organizations using Halo CMS or related Halo-hosted services, this vulnerability poses a moderate risk. Attackers could craft malicious URLs to trick employees or customers into executing scripts that steal session tokens or perform unauthorized actions within the web application context. This could lead to account compromise, data leakage, or unauthorized content manipulation. While the vulnerability does not directly impact system availability, the loss of confidentiality and integrity could undermine trust in affected services, especially those handling sensitive or regulated data. Organizations in sectors such as finance, healthcare, and government are particularly sensitive to such breaches. Additionally, the scope change in the vulnerability means that an exploit could impact other components or user sessions beyond the immediate vulnerable endpoint, increasing potential damage. The requirement for user interaction reduces the risk somewhat but does not eliminate it, as phishing or social engineering campaigns can be effective. The absence of known exploits in the wild provides a window for proactive mitigation before active attacks emerge.

European organizations should implement the following specific mitigations: 1) Immediately audit and sanitize all user inputs in the /halo_host/archives/{name} endpoint, ensuring proper encoding and escaping of special characters to prevent script injection. 2) Deploy Web Application Firewalls (WAFs) with rules targeting reflected XSS patterns on the affected URL paths to block malicious payloads. 3) Educate users and staff about the risks of clicking untrusted links, especially those purporting to come from internal or trusted sources. 4) Monitor web server logs for unusual or suspicious requests to the vulnerable endpoint that may indicate exploitation attempts. 5) Engage with the Halo vendor or community to obtain or request patches or updates addressing this vulnerability as soon as they become available. 6) Implement Content Security Policy (CSP) headers to restrict the execution of inline scripts and reduce the impact of potential XSS attacks. 7) Regularly review and update incident response plans to include scenarios involving XSS exploitation and data leakage. These steps go beyond generic advice by focusing on the specific vulnerable endpoint, user education, and layered defenses.