CVE-2026-2622 is a cross-site scripting (XSS) vulnerability identified in Blossom, a content management system, affecting versions 1.17.0 and 1.17.1. The flaw exists in the Article Title Handler component, specifically within the ArticleController.java file located at blossom-backend/backend/src/main/java/com/blossom/backend/server/article/draft/. The vulnerability stems from insufficient sanitization or encoding of user-supplied input in the 'content' function, allowing attackers to inject malicious JavaScript code. This injected script executes in the context of users who view the compromised article drafts, 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 user interaction is necessary to trigger the payload, such as viewing a maliciously crafted article. The vendor was notified early but has not issued a patch or response, and public exploit code is available, increasing the risk of exploitation. The CVSS 4.0 base score is 5.1, reflecting medium severity, with attack vector network, low attack complexity, no privileges required, and user interaction needed. The vulnerability impacts confidentiality and integrity but not availability. No known exploits in the wild have been reported yet, but the public availability of exploit code suggests potential imminent attacks. The lack of vendor response and patch availability necessitates immediate mitigation efforts by users of Blossom.

For European organizations using Blossom CMS, this vulnerability poses a risk to the confidentiality and integrity of their web applications and user data. Successful exploitation could lead to session hijacking, enabling attackers to impersonate legitimate users, steal sensitive information, or perform unauthorized actions. This can damage organizational reputation, lead to data breaches, and disrupt business operations. Since Blossom is used for content management, compromised article drafts could be used to spread malware or phishing content to visitors, amplifying the impact. The remote exploitability without authentication increases the attack surface, especially for public-facing systems. The absence of vendor patches means organizations must rely on internal mitigations, increasing operational overhead. European entities in sectors such as media, publishing, education, and government that rely on Blossom for content delivery are particularly vulnerable. Additionally, regulatory frameworks like GDPR impose strict data protection requirements, and exploitation could result in compliance violations and financial penalties.

1. Implement strict input validation and output encoding on all user-supplied data, especially in the Article Title Handler component, to neutralize malicious scripts. 2. Deploy Web Application Firewalls (WAFs) with custom rules to detect and block XSS payloads targeting Blossom endpoints. 3. Restrict access to article draft editing and viewing interfaces to authenticated and authorized users only, minimizing exposure. 4. Monitor web server and application logs for unusual requests or script injection attempts related to the vulnerable component. 5. Educate content editors and users to be cautious of suspicious links or content within the CMS. 6. If possible, isolate Blossom instances from critical internal networks to limit lateral movement in case of compromise. 7. Regularly back up content and configurations to enable recovery from potential defacement or data corruption. 8. Engage with the Blossom vendor or community to track patch releases and apply updates promptly once available. 9. Consider temporary disabling or restricting the vulnerable Article Title Handler functionality if feasible until a patch is released. 10. Conduct security assessments and penetration testing focused on XSS vulnerabilities within Blossom deployments.