3 High-Severity HP Easy Start Flaws Allow Privilege Escalation on macOS

Key Takeaways

• Three high-severity vulnerabilities in HP Easy Start for macOS could lead to privilege escalation.
• The flaws affect versions of HP Easy Start for macOS older than 2.16.7.260722.
• Attackers could exploit weaknesses in download mechanisms, temporary file handling, and network transport settings.
• HP has released a patched version (2.16.7.260722) to address these issues.

HP Easy Start Flaws Expose macOS Users to Privilege Escalation

Three critical vulnerabilities have been identified in HP Easy Start for macOS, potentially allowing malicious actors to interfere with printer software installation processes and escalate privileges on affected systems. These flaws impact versions preceding 2.16.7.260722 of the application. HP has since rolled out an updated version that mitigates these risks.

The vulnerabilities, tracked as CVE-2026-12554, CVE-2026-12555, and CVE-2026-12556, collectively target the application’s download mechanisms, its handling of temporary files, and its network transport configurations. HP Easy Start, designed to facilitate printer setup, performs privileged installation operations, making it a prime target for attacks that manipulate files or software packages requiring administrative permissions.

Deep Dive into the Vulnerabilities

The most critical of the three, CVE-2026-12554, carries a CVSS 4.0 score of 8.5. This vulnerability is categorized under CWE-1104, indicating the use of unmaintained third-party components. Researchers discovered that the vulnerable application integrated an OSPFTP download stack within its software installation workflow. This component’s capability to fall back to FTP for downloads is a significant concern, as FTP inherently lacks encryption for data transfers and offers no robust integrity protections.

An attacker operating within the same network, or one capable of manipulating DNS resolution, could exploit this fallback mechanism. By intercepting unencrypted FTP traffic, they could potentially tamper with software downloads, especially if the application defaults to FTP under certain conditions.

While the presence of an outdated FTP component doesn’t guarantee that every HP Easy Start installation will use FTP or that package-signature checks are always bypassed, it undeniably broadens the attack surface of a privileged installer. This legacy component introduces an unnecessary risk vector into a process that typically requires elevated system permissions.

CVE-2026-12555, with a CVSS score of 7.7, is linked to CWE-379, an insecure temporary-file issue. This flaw specifically affects the HP Uninstaller component, which was found to create temporary files using predictable paths within the /tmp and /private/tmp directories while operating with administrator privileges. A local attacker with access to the macOS system could pre-create a symbolic link at one of these predictable locations. When a legitimate user then launches the HP uninstaller and approves the administrator prompt, the elevated process might follow the attacker-controlled link, writing application-generated log data to an arbitrary, attacker-chosen destination.

While this vulnerability doesn’t grant full control over the content written by the application, it enables privileged file modification or corruption. Manipulating sensitive configuration or service-related files through this method could lead to denial-of-service conditions or facilitate further attacks within specific environments.

The third vulnerability, CVE-2026-12556, also rated 7.7 under CVSS 4.0, is mapped to CWE-319, cleartext transmission of sensitive information. The vulnerable builds of HP Easy Start had globally relaxed macOS App Transport Security (ATS) settings by enabling the NSAllowsArbitraryLoads option. This setting permits insecure HTTP connections that macOS would typically block. In conjunction with the FTP fallback capability, this relaxed transport policy significantly heightens the risk of cleartext software delivery. A network-positioned attacker could exploit this to manipulate downloaded components, particularly if other package integrity controls are weak or improperly enforced.

Security researcher Nir Yehoshua of Cipher Security Labs discovered the issues during an assessment of HP Easy Start version 2.16.0, build 251010.

Patch and Mitigation

HP addressed these three vulnerabilities in HP Easy Start version 2.16.7.260722. This updated release reportedly removes the vulnerable uninstaller paths, eliminates the problematic OSPFTP download component, and tightens the application’s transport security configuration. HP’s official advisory was published on August 24, 2026.

What You Should Do

• Immediately update HP Easy Start for macOS to version 2.16.7.260722 or a later version.
• Administrators should conduct a thorough review of all macOS systems to identify and update any installations of HP Easy Start that are still running older, vulnerable versions.
• Pay particular attention to shared Macs where local attackers might exploit temporary directories, and enterprise networks where unencrypted traffic could be exposed.

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