CVE-2025-11945 identifies a cross-site scripting (XSS) vulnerability in the toeverything AFFiNE software, versions 0.24.0 and 0.24.1. The vulnerability resides in the Avatar Upload Image Endpoint, where insufficient input sanitization allows an attacker to inject malicious scripts. This flaw can be exploited remotely without authentication, though user interaction is necessary to trigger the payload, such as by viewing a crafted avatar image or manipulated content. The vulnerability impacts the integrity and availability of user sessions by enabling script execution in the victim’s browser context, potentially leading to session hijacking, defacement, or phishing attacks. The CVSS 4.0 score is 5.1 (medium severity), reflecting the ease of remote exploitation with low attack complexity but requiring user interaction and limited impact on confidentiality. The vendor has not issued a patch or responded to disclosure, and exploit code is publicly available, increasing the risk of exploitation in the wild. AFFiNE is a collaborative platform, and the Avatar Upload feature is commonly used in user profiles, making this endpoint a likely attack vector. Without vendor mitigation, organizations must rely on defensive controls and configuration changes to reduce exposure.

For European organizations, this vulnerability poses a risk primarily to the integrity and availability of user sessions within AFFiNE deployments. Attackers could exploit the XSS flaw to execute malicious scripts in users’ browsers, potentially stealing session tokens, performing actions on behalf of users, or delivering phishing content. This could lead to unauthorized access to sensitive collaboration data or disruption of services. Since AFFiNE is used in collaborative environments, the impact could extend to internal communications and project data confidentiality indirectly through social engineering. The lack of vendor response and patches increases the window of exposure. Organizations with public-facing AFFiNE instances or those allowing external users to upload avatars are at higher risk. The exploit’s requirement for user interaction means targeted phishing or social engineering campaigns could amplify the threat. Overall, the vulnerability could undermine trust in collaboration platforms and lead to data leakage or operational disruption.

1. Temporarily disable the Avatar Upload Image feature in AFFiNE until a vendor patch is available to eliminate the attack surface. 2. Implement strict input validation and output encoding on all user-supplied data, especially image upload metadata and filenames, to prevent script injection. 3. Deploy a web application firewall (WAF) with rules specifically designed to detect and block XSS payloads targeting the avatar upload endpoint. 4. Educate users about the risks of clicking on suspicious links or viewing untrusted content within AFFiNE to reduce successful exploitation via social engineering. 5. Monitor logs and network traffic for unusual activity related to avatar uploads or script execution attempts. 6. If possible, sandbox or isolate the avatar upload processing to limit potential damage from malicious payloads. 7. Engage with the vendor or community to encourage patch development and share threat intelligence. 8. Review and enforce Content Security Policy (CSP) headers to restrict script execution origins in AFFiNE deployments.