CVE-2025-53275 is a Cross-site Scripting (XSS) vulnerability classified under CWE-79, specifically a DOM-Based XSS issue found in the VaultDweller Leyka product, affecting versions up to 3.31.9. This vulnerability arises from improper neutralization of input during web page generation, allowing malicious scripts to be injected and executed in the context of a user's browser. The vulnerability is exploitable remotely (AV:N), requires low attack complexity (AC:L), but does require privileges (PR:L) and user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact includes low confidentiality, integrity, and availability impacts (C:L/I:L/A:L), indicating that while the vulnerability can lead to some data exposure or manipulation and disruption, it is not catastrophic. DOM-Based XSS means the malicious payload is executed as a result of modifying the DOM environment in the victim's browser, rather than being directly reflected from server responses, complicating detection and mitigation. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was published on June 27, 2025, and is rated medium severity with a CVSS score of 6.5. Given the nature of the vulnerability, attackers could leverage it to steal session tokens, perform actions on behalf of users, or redirect users to malicious sites, potentially leading to further compromise or data leakage.

For European organizations using VaultDweller Leyka, this vulnerability poses a moderate risk. Since Leyka is a product that may be used in various sectors, including potentially sensitive environments, exploitation could lead to unauthorized access to user sessions or manipulation of web application behavior. This can result in data breaches, loss of user trust, and compliance issues under regulations such as GDPR, especially if personal data is exposed or manipulated. The requirement for user interaction and privileges limits the attack surface somewhat, but social engineering or insider threats could still enable exploitation. The scope change indicates that the impact could extend beyond the immediate application, potentially affecting integrated systems or services. The absence of known exploits suggests a window for proactive mitigation, but organizations should act promptly to prevent exploitation. The medium severity rating reflects a balance between the ease of exploitation and the potential damage, emphasizing the need for timely remediation to avoid escalation or chaining with other vulnerabilities.

European organizations should implement the following specific mitigations: 1) Conduct an immediate audit of all instances of VaultDweller Leyka to identify affected versions and prioritize upgrades once patches are available. 2) Apply strict Content Security Policy (CSP) headers to restrict the execution of untrusted scripts and reduce the risk of DOM-based XSS exploitation. 3) Implement input validation and output encoding on the client side to sanitize any user-controllable inputs that interact with the DOM. 4) Educate users about the risks of interacting with suspicious links or content that could trigger XSS attacks, reducing the likelihood of successful social engineering. 5) Monitor web application logs and user behavior for anomalies indicative of XSS exploitation attempts. 6) Employ web application firewalls (WAFs) with rules tailored to detect and block DOM-based XSS payloads, although recognizing that DOM XSS can be challenging to detect at the network level. 7) Prepare incident response plans specifically addressing XSS incidents to enable rapid containment and remediation. 8) Engage with VaultDweller support or security teams to obtain patches or workarounds as soon as they are released.