CVE-2026-0824 identifies a cross-site scripting (XSS) vulnerability in the QuestDB UI Web Console component, affecting versions 1.11.0 through 1.11.9. The vulnerability arises from insufficient sanitization of user-controllable input within an unspecified function of the Web Console, allowing attackers to inject malicious JavaScript code. This injected script can execute in the context of the victim's browser when they interact with the affected UI, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the user. The attack vector is remote and does not require authentication, but does require user interaction to trigger the malicious payload. The CVSS 4.0 score of 5.1 reflects a medium severity, considering the attack complexity is low, no privileges are required, but user interaction is necessary. The vulnerability does not impact confidentiality or availability significantly but poses a risk to integrity and user trust. The vendor has addressed the issue in QuestDB UI version 1.1.10 and plans to include the fix in the upcoming QuestDB 9.3.0 release. Public exploit code has been released, increasing the risk of exploitation, although no widespread attacks have been reported yet.

For European organizations, the impact of CVE-2026-0824 is primarily related to the compromise of user sessions and potential unauthorized actions within the QuestDB Web Console. This could lead to data integrity issues, unauthorized data queries or modifications, and exposure of sensitive operational information. While the vulnerability does not directly lead to data exfiltration or system takeover, the ability to execute scripts in users' browsers can facilitate phishing, credential theft, or lateral movement within the network. Organizations using QuestDB for critical data analytics or real-time database management may face operational disruptions or reputational damage if attackers exploit this vulnerability. The public availability of exploit code increases the urgency for patching, especially in sectors with high regulatory scrutiny such as finance, healthcare, and government within Europe. The medium severity indicates that while the threat is not critical, it should not be ignored, particularly in environments where QuestDB UI is exposed to untrusted networks or users.

To mitigate CVE-2026-0824, European organizations should immediately upgrade QuestDB UI to version 1.1.10 or later, or apply the vendor's patch as soon as it becomes available in QuestDB 9.3.0. Network segmentation should be employed to restrict access to the QuestDB Web Console to trusted internal users only, minimizing exposure to remote attackers. Implementing Content Security Policy (CSP) headers can help reduce the impact of XSS by restricting the execution of unauthorized scripts. Regularly audit and sanitize all user inputs and outputs within custom integrations or extensions of QuestDB UI. Employ multi-factor authentication (MFA) to reduce the risk of session hijacking. Monitor logs for unusual activity related to the Web Console and conduct periodic security assessments focusing on web application vulnerabilities. Educate users about the risks of interacting with suspicious links or content that could trigger XSS attacks. Finally, maintain an up-to-date inventory of QuestDB deployments to ensure timely patch management.