CVE-2026-0824 is a medium severity cross-site scripting vulnerability found in the QuestDB UI Web Console component, affecting versions 1.11.0 through 1.11.9. The vulnerability arises from improper input sanitization or output encoding in an unspecified function of the Web Console, allowing remote attackers to inject malicious JavaScript code. This XSS flaw can be exploited remotely without authentication but requires user interaction, such as a victim clicking a crafted link or visiting a malicious page. Successful exploitation could enable attackers to execute scripts in the context of the victim's browser session, potentially leading to session hijacking, defacement, or limited data manipulation. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges required, user interaction needed, and limited impact on confidentiality and integrity, with no impact on availability. The vendor has released a patch in version 1.1.10 and plans to include the fix in QuestDB 9.3.0. Although public exploit code exists, no confirmed widespread exploitation has been reported. Organizations using affected QuestDB UI versions should prioritize upgrading to mitigate this risk.

For European organizations, the impact of this XSS vulnerability primarily concerns web application security and user trust. Attackers exploiting this flaw could execute malicious scripts in users' browsers, potentially stealing session tokens, redirecting users to phishing sites, or manipulating displayed data. While the confidentiality and integrity impact is limited, successful attacks could lead to unauthorized access to user sessions or data exposure within the affected UI. This could disrupt business operations, damage reputation, and lead to compliance issues under GDPR if personal data is exposed. Organizations relying on QuestDB UI for database management or analytics, especially in sectors like finance, healthcare, or critical infrastructure, may face increased risk. The requirement for user interaction reduces the likelihood of automated mass exploitation but targeted phishing or social engineering attacks remain a concern. Prompt patching is essential to prevent exploitation and maintain secure operations.

1. Upgrade immediately to QuestDB UI version 1.1.10 or later, or wait for the inclusion of the fix in QuestDB 9.3.0 if upgrading the full platform. 2. Implement Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in the web console environment. 3. Educate users on the risks of clicking untrusted links or interacting with suspicious content related to QuestDB UI. 4. Monitor web server and application logs for unusual requests or signs of attempted XSS exploitation. 5. Employ web application firewalls (WAF) with rules tuned to detect and block XSS payloads targeting the QuestDB UI. 6. Conduct regular security assessments and penetration testing focused on the Web Console interface to identify residual or related vulnerabilities. 7. Review and harden input validation and output encoding practices in any custom integrations with QuestDB UI. 8. Isolate the QuestDB UI access to trusted networks or VPNs where feasible to reduce exposure.