External risk intelligence

Adobe Connect could allow an external attacker to run unauthorized code on user devices.

CVE advisorySeverity: CRITICAL (CVSS 9.6)

CVE-2026-27303

An external attacker can exploit Adobe Connect by tricking employees into clicking malicious links, enabling the execution of unauthorized code on their devices. This could allow attackers to steal sensitive meeting data and confidential files, resulting in the compromise of organizational information.

1Halo Surface Signal

Deserialization

Adobe Connect

before 12.112025.3 and earlierbefore 2025.9.15

External exposure likelihood

Halo Surface Signal score for CVE-2026-27303

The vulnerability is client-side, requiring an authenticated user to manually interact with a malicious link or web page to trigger the issue. Because it depends on user-initiated interaction rather than being an unauthenticated, directly exposed network service, API, or internet-facing gateway, it does not fit the criteria for a widely exposed public internet surface.

Horizon Alert

Summary of the vulnerability and why it matters

This issue in Adobe Connect allows an attacker to execute malicious code on a user's computer if that user visits a specially crafted link or a compromised webpage. This could lead to sensitive information being compromised or systems being further exploited.

  • Requires user interaction to exploit.
  • Can lead to code execution.

Attack Path

How an attacker could exploit the issue

An attacker can achieve arbitrary code execution by tricking a user into clicking a malicious link or visiting a compromised website. This would trigger a deserialization vulnerability in Adobe Connect, allowing the attacker to run code with the user's permissions on their system. The attack requires the user to actively engage with the malicious content.

  • Requires user interaction.
  • Targets Adobe Connect.
  • Allows code execution.

Live Threat

Current exploitation, exposure, and threat context

This deserialization vulnerability, requiring user interaction through a malicious link or web page, presents a moderate threat. While it can lead to code execution, the need for victim engagement limits widespread, automated exploitation. Attackers might favor this if targeting specific individuals or organizations where social engineering is viable.

  • Requires user interaction.
  • No public exploit observed.
  • No KEV signal.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

Prioritize isolating or taking offline affected Adobe Connect services due to a critical deserialization vulnerability. This requires user interaction, but successful exploitation can lead to arbitrary code execution. Teams should focus on identifying and blocking malicious URLs targeting this vulnerability while assessing the full scope of affected users and assets.

  • Patch Adobe Connect to the latest version.
  • Block malicious URLs and monitor for suspicious activity.
  • Inventory affected Adobe Connect instances.

Frequently asked questions

What is Adobe Connect?

Adobe Connect is a web conferencing platform designed for online meetings, webinars, and virtual classrooms. It facilitates remote content sharing, real-time collaboration, and the delivery of training or presentations.

What type of vulnerability affects Adobe Connect?

Adobe Connect is affected by a Deserialization of Untrusted Data vulnerability. This weakness allows an attacker to potentially execute arbitrary code on a user's system with their current privileges.

How can an attacker exploit this Adobe Connect vulnerability?

Exploitation requires a user to interact with a maliciously crafted URL or a compromised webpage. This user interaction is necessary to trigger the vulnerability and is a key step in the attack chain.

What is the relevance of CVE-2026-27303 to user security?

This critical vulnerability, CVE-2026-27303, poses a significant risk as it can allow an external attacker to execute unauthorized code on user devices. Successful exploitation can lead to sensitive information compromise or further system exploitation.

What actions should be taken regarding this Adobe Connect vulnerability?

Prioritize patching Adobe Connect to the latest version to address the critical deserialization vulnerability. Additionally, teams should focus on identifying and blocking malicious URLs and monitoring for suspicious activity.

References