CVE-2025-62584 is a security vulnerability identified in the NAVER Whale browser, specifically affecting versions before 4.33.325.17. The root cause is an origin validation error classified under CWE-346, which leads to a Same-Origin Policy (SOP) bypass in a dual-tab environment. The SOP is a critical browser security mechanism that restricts how documents or scripts loaded from one origin can interact with resources from another origin. This vulnerability allows an attacker to circumvent these restrictions by exploiting improper origin checks when multiple tabs are open simultaneously. An attacker could craft malicious web content that, when opened in a separate tab alongside a legitimate site, can access or manipulate sensitive data from the legitimate tab’s origin. This could lead to unauthorized data disclosure, session hijacking, or other cross-origin attacks. The vulnerability does not require prior authentication but does require user interaction to open the malicious tab. No public exploits have been reported yet, and no CVSS score has been assigned. The flaw impacts the confidentiality and integrity of user data by allowing cross-origin data leakage or manipulation. The vendor has not yet provided patch links, but users are advised to update to version 4.33.325.17 or later once available. This issue highlights the importance of robust origin validation in browser security, especially in multi-tab browsing contexts.

For European organizations, this vulnerability poses a significant risk to data confidentiality and integrity, especially for those relying on the NAVER Whale browser for web access. Attackers could exploit this flaw to steal sensitive corporate information, session tokens, or perform unauthorized actions on behalf of users by leveraging cross-origin data access. This is particularly concerning for sectors handling sensitive personal data, financial information, or intellectual property. The vulnerability could facilitate targeted attacks such as phishing or corporate espionage. Given the browser’s niche market share in Europe, the impact may be limited to organizations or users who have adopted Whale, but those affected could face serious data breaches or compliance violations under GDPR. The absence of known exploits reduces immediate risk but does not eliminate the threat, as attackers may develop exploits once the vulnerability becomes widely known. The dual-tab requirement means user behavior influences exploitability, but the risk remains relevant in typical browsing scenarios.

Organizations should prioritize updating the NAVER Whale browser to version 4.33.325.17 or later once the patch is released by the vendor. Until then, users should be advised to avoid opening untrusted or suspicious websites in multiple tabs simultaneously within the Whale browser. Implementing browser usage policies that restrict or monitor Whale browser deployment can reduce exposure. Network-level controls such as web filtering and endpoint security solutions can help detect and block malicious web content attempting to exploit this vulnerability. Security teams should educate users about the risks of opening unknown links in new tabs and encourage the use of alternative browsers with stronger security track records if Whale is not essential. Monitoring for unusual browser behavior or cross-origin data access attempts can provide early detection. Finally, organizations should engage with NAVER for timely updates and consider sandboxing or isolating Whale browser sessions in high-risk environments.