CVE-2026-0291 in Prisma Access Agent
Summary
by MITRE • 08/13/2026
An improper link resolution before file access vulnerability exists in the Palo Alto Networks Prisma® Access Agent on Linux platforms that enables a local low privileged user to delete system files in a limited scope and disable Prisma Access Agent.
The Prisma Access Agent on macOS, Windows, iOS, Android, and Chrome OS is not affected.
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Analysis
by VulDB Data Team • 08/13/2026
This vulnerability represents a critical improper link resolution issue that specifically targets the Linux implementation of Palo Alto Networks Prisma Access Agent. The flaw resides in how the agent handles symbolic links during file access operations, creating a path traversal condition that allows local users to manipulate file system operations beyond their intended scope. This weakness falls under the CWE-367 category of Time-of-Check to Time-of-Use (TOCTOU) vulnerabilities, where the system checks for permissions or file existence at one point but then accesses different files at another point due to link resolution timing issues.
The technical implementation of this vulnerability enables a low privileged user to exploit a race condition in the agent's file handling mechanism. When the Prisma Access Agent processes file operations on Linux systems, it fails to properly validate symbolic links before executing file access commands. This allows an attacker to create malicious symbolic links that point to critical system files, then manipulate the agent into deleting or modifying these targets during legitimate file operations. The vulnerability specifically impacts the agent's ability to maintain system integrity and operational continuity, as demonstrated by the reported capability to disable the agent itself.
The operational impact of this vulnerability extends beyond simple file deletion capabilities, as it fundamentally compromises the integrity and availability of the Prisma Access Agent service on affected Linux platforms. Attackers can leverage this weakness to disrupt network security operations by removing critical agent components or system files necessary for proper agent functionality. The scope limitation mentioned in the description suggests that while the attacker cannot delete arbitrary system files across the entire system, they can target specific agent-related files and directories, potentially leading to complete service disruption. This aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1486 for Data Encrypted for Ransomware, as the compromised agent could be used as a foothold for more extensive attacks.
Organizations deploying Prisma Access Agent on Linux systems face significant risk exposure from this vulnerability, particularly in environments where local user access is not strictly controlled. The attack vector requires local system access but does not demand elevated privileges, making it accessible to users with minimal system rights. This characteristic makes the vulnerability particularly dangerous in multi-tenant or shared computing environments where privilege separation may be insufficient. The impact on agent functionality could result in service interruptions, loss of network monitoring capabilities, and potential security gaps that attackers could exploit for further lateral movement within the network infrastructure.
Mitigation strategies should focus on immediate patching of affected Linux implementations, though organizations without access to official patches should consider implementing strict file system permissions and symbolic link restrictions. Network segmentation and privilege separation measures can help limit the scope of potential exploitation, while monitoring for unauthorized symbolic link creation activities provides additional detection capabilities. The vulnerability highlights the importance of proper input validation and secure file handling practices, particularly when dealing with user-controlled paths in security agent implementations. Organizations should also consider implementing automated compliance checks to verify that symbolic link resolution is properly handled within their Prisma Access Agent deployments across all supported platforms.
The fact that macOS, Windows, iOS, Android, and Chrome OS versions remain unaffected indicates that the vulnerability is specific to the Linux implementation's file system handling logic, suggesting that other platforms have implemented proper path validation mechanisms. This platform-specific nature aligns with common security vulnerabilities where different operating systems handle file operations differently, and the absence of similar issues in other implementations demonstrates the importance of cross-platform security testing and consistent implementation of secure coding practices across all supported environments.