Adobe Connect DOM-based XSS Vulnerability

Adobe Connect versions 2025.3, 12.10, and earlier are susceptible to a DOM-based Cross-Site Scripting (XSS) vulnerability (CVE-2026-27246). This vulnerability allows an attacker to inject and execute arbitrary JavaScript code within a user's browser session when they visit a specially crafted webpage. The attack requires user interaction, where the victim must be enticed to click a link or otherwise access the malicious page. Successful exploitation could lead to session hijacking, defacement, or the theft of sensitive information. This vulnerability poses a significant risk to organizations relying on Adobe Connect for online meetings, webinars, and e-learning. The vulnerability was reported on April 14, 2026.

Attack Chain

1. Attacker crafts a malicious webpage containing JavaScript designed to exploit the DOM-based XSS vulnerability in Adobe Connect.
2. The attacker hosts the malicious page on a publicly accessible server.
3. The attacker distributes the malicious link to potential victims via email, social media, or other means.
4. A victim clicks on the link, causing their browser to load the attacker's webpage.
5. The malicious JavaScript on the page manipulates the DOM environment of the Adobe Connect application running in the victim's browser.
6. The injected JavaScript executes within the context of the victim's Adobe Connect session, potentially gaining access to sensitive data or performing unauthorized actions.
7. The attacker uses the XSS to redirect the user to a fake login page and steal credentials.
8. The attacker uses the stolen credentials to gain unauthorized access to the victim's Adobe Connect account.

Impact

Successful exploitation of this DOM-based XSS vulnerability could allow attackers to steal sensitive information, such as user credentials or meeting content. An attacker can also perform actions on behalf of the user, potentially disrupting meetings or webinars. The impact ranges from defacement of the Adobe Connect interface to complete account takeover. Given the reliance of many organizations on Adobe Connect for remote collaboration and communication, a widespread attack could result in significant operational disruption and data breaches.

Recommendation

• Apply the security patch provided by Adobe in APSB26-37 to remediate CVE-2026-27246.
• Deploy the Sigma rule Detect Suspicious URI Query Parameters to identify potential XSS attempts targeting Adobe Connect via crafted URLs.
• Implement user awareness training to educate users about the risks of clicking suspicious links.
• Monitor web server logs for unusual activity, specifically requests containing suspicious URI parameters, as indicated by the log source in the Sigma rule Detect Suspicious URI Query Parameters.