CVE-2026-27245: Adobe Connect Reflected XSS Vulnerability

CVE-2026-27245 Overview

Adobe Connect versions 2025.3, 12.10 and earlier are affected by a reflected Cross-Site Scripting (XSS) vulnerability. If an attacker is able to convince a victim to visit a URL referencing a vulnerable page, malicious JavaScript content may be executed within the context of the victim's browser. This vulnerability has a changed scope, meaning the impact extends beyond the vulnerable component itself.

Critical Impact

This reflected XSS vulnerability allows attackers to execute arbitrary JavaScript in victim browsers, potentially leading to session hijacking, credential theft, and unauthorized actions within Adobe Connect environments.

Affected Products

• Adobe Connect version 2025.3 and earlier
• Adobe Connect version 12.10 and earlier
• All Adobe Connect installations prior to security patch APSB26-37

Discovery Timeline

• 2026-04-14 - CVE-2026-27245 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2026-27245

Vulnerability Analysis

This reflected Cross-Site Scripting (XSS) vulnerability in Adobe Connect stems from improper neutralization of user-supplied input before it is rendered in web pages (CWE-79). The vulnerability requires user interaction—specifically, the victim must be tricked into clicking a malicious URL that contains the XSS payload. Once clicked, the malicious JavaScript executes within the security context of the victim's authenticated session on the Adobe Connect platform.

The "changed scope" designation indicates that the vulnerability in Adobe Connect can impact resources beyond its own security scope, potentially affecting the victim's browser session with other web applications or enabling attacks against the broader organizational environment where Adobe Connect is deployed.

Root Cause

The root cause is improper input validation and output encoding (CWE-79 - Improper Neutralization of Input During Web Page Generation). User-controlled input is reflected back in HTTP responses without adequate sanitization, allowing attackers to inject malicious script content that executes in the victim's browser context.

Attack Vector

The attack requires network access and user interaction. An attacker crafts a malicious URL containing JavaScript payload and distributes it through phishing emails, social media, or other communication channels. When a victim with an active Adobe Connect session clicks the link, the malicious script executes with the victim's privileges, potentially allowing:

• Session token theft and account takeover
• Performing actions on behalf of the authenticated user
• Redirecting users to malicious sites
• Capturing sensitive information displayed in the application

The attack does not require authentication from the attacker's perspective, making it particularly dangerous in enterprise environments where Adobe Connect is used for virtual meetings and collaboration.

Detection Methods for CVE-2026-27245

Indicators of Compromise

• Unusual URL patterns in web server logs containing encoded JavaScript or script tags directed at Adobe Connect endpoints
• Phishing emails or messages containing Adobe Connect URLs with suspicious query parameters
• Users reporting unexpected redirects or browser behavior after clicking Adobe Connect links
• Anomalous session activity following link clicks, such as configuration changes or data exports

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block common XSS payloads in requests to Adobe Connect
• Monitor proxy and web server logs for URL patterns containing encoded script elements or event handlers
• Deploy browser security controls that report Content Security Policy violations
• Use endpoint detection to identify unusual JavaScript execution patterns following visits to Adobe Connect URLs

Monitoring Recommendations

• Enable detailed logging for Adobe Connect web server access to capture full request URLs
• Configure SIEM alerts for patterns indicative of reflected XSS attempts targeting collaboration platforms
• Monitor for phishing campaigns that reference Adobe Connect domains with suspicious parameters
• Review authentication logs for session anomalies that may indicate post-exploitation activity

How to Mitigate CVE-2026-27245

Immediate Actions Required

• Update Adobe Connect to the latest patched version as specified in security bulletin APSB26-37
• Implement Content Security Policy (CSP) headers to restrict script execution sources
• Enable HTTPOnly and Secure flags on all session cookies
• Educate users about the risks of clicking untrusted links, even those appearing to reference legitimate Adobe Connect URLs

Patch Information

Adobe has released a security patch addressing this vulnerability. Organizations should apply the update referenced in Adobe Security Bulletin APSB26-37 immediately. The patch addresses the improper input validation that allows reflected XSS attacks.

Workarounds

• Deploy a web application firewall (WAF) with XSS detection rules in front of Adobe Connect servers
• Implement strict Content Security Policy headers to prevent inline script execution
• Use URL filtering at the network perimeter to block suspicious Adobe Connect URLs with potentially malicious parameters
• Consider disabling or restricting access to Adobe Connect features until patching is complete in high-risk environments

# Example Content Security Policy header configuration for Apache
# Add to Adobe Connect virtual host configuration
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; frame-ancestors 'self';"
Header set X-XSS-Protection "1; mode=block"
Header set X-Content-Type-Options "nosniff"