CVE-2026-78547 in Workspace App
Summary
by MITRE • 09/11/2026
Out-of-bounds write vulnerability in Citrix Citrix Workspace app for Windows.
This issue affects Citrix Workspace app for Windows: before 2603.11 Current Release (CR), before 2507.1 LTSR CU3, and before LTSR 2607.
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Analysis
by VulDB Data Team • 09/11/2026
The identified vulnerability represents a critical out-of-bounds write condition within the Citrix Workspace application for Windows environments. This flaw allows an attacker to write data beyond the boundaries of allocated memory buffers, potentially leading to arbitrary code execution or system instability. The issue impacts multiple versions of the software, specifically affecting releases prior to 2603.11 in the Current Release track and before 2507.1 LTSR CU3 as well as earlier builds within the Long Term Service Release (LTSR) 2607 branch. Such vulnerabilities are particularly dangerous because they can be exploited through crafted inputs that trigger memory corruption, bypassing standard security controls if not properly mitigated by version updates or configuration hardening.
From a technical perspective, out-of-bounds write errors fall under the Common Weakness Enumeration category CWE-787, which describes writing to a memory location outside of the intended buffer boundary. This type of flaw often arises from insufficient validation of input data lengths or improper handling of array indices during processing operations within the application logic. When an attacker supplies maliciously crafted data that exceeds expected limits, the application may overwrite adjacent memory structures, including control flow data such as return addresses or function pointers. In complex applications like Citrix Workspace, which handles extensive user interactions and network communications, these errors can be triggered through specific API calls or UI actions designed to manipulate internal state variables in unintended ways.
The operational impact of this vulnerability is severe, potentially allowing remote attackers to execute arbitrary code with the privileges of the affected application process. If successful exploitation occurs, it could lead to a complete compromise of the endpoint running the Citrix client, enabling data exfiltration, lateral movement within the network, or establishment of persistent backdoors. Given that Citrix Workspace is often used in enterprise environments for secure remote access and virtual desktop infrastructure connections, compromising this application can serve as an entry point into broader corporate networks. Attackers may leverage this flaw to escalate privileges, install malware, or disrupt critical business operations by causing denial-of-service conditions through memory corruption crashes.
Mitigation strategies must prioritize immediate patching of the affected software versions. Administrators should upgrade Citrix Workspace app for Windows to version 2603.11 Current Release or later, or ensure that LTSR deployments are updated to at least 2507.1 CU3 and LTSR 2607 respectively. In cases where immediate patching is not feasible due to compatibility constraints, network segmentation should be enforced to restrict access to the vulnerable application from untrusted networks. Additionally, deploying endpoint detection and response solutions with behavioral analysis capabilities can help identify anomalous memory access patterns indicative of exploitation attempts. Regular vulnerability scanning and adherence to secure coding practices during future development cycles are essential to prevent recurrence of such memory safety issues in line with industry standards like OWASP guidelines for input validation and buffer management.