CVE-2026-91106 in HPLIP
Summary
by MITRE • 09/16/2026
HP has identified and remediated multiple externally reported vulnerabilities within HPLIP. The findings affect several software components that could potentially enable remote code execution, privilege escalation, denial of service, information disclosure, or unauthorized file modification under certain conditions.
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Analysis
by VulDB Data Team • 09/16/2026
Hewlett-Packard has addressed a cluster of security flaws identified in the HP Linux Imaging and Printing (HPLIP) suite, resolving issues reported by external researchers that pose significant risks to system integrity and confidentiality. These vulnerabilities span multiple software components within the HPLIP ecosystem, creating attack surfaces that can be exploited under specific conditions to achieve severe outcomes including remote code execution, privilege escalation, denial of service, information disclosure, and unauthorized file modification. The remediation efforts underscore the critical nature of maintaining up-to-date printer driver stacks in enterprise environments where automated printing workflows are prevalent.
The potential for remote code execution represents one of the most critical risks associated with these flaws. If an attacker can trigger specific input vectors within the HPLIP components, they may execute arbitrary commands on the host system with the privileges of the user running the application or potentially higher if privilege escalation is successful. This aligns with CWE-94 Improper Control of Generation of Code (Code Injection) and CWE-78 OS Command Injection, depending on how the input is processed. In many Linux environments, HPLIP runs as a regular user but may interact with system-level resources or devices that require elevated permissions, thereby increasing the blast radius if an injection vulnerability is exploited.
Privilege escalation vulnerabilities further compound the threat landscape by allowing attackers to transition from low-privileged contexts to higher levels of access, such as root or SYSTEM privileges. This often occurs due to improper handling of file permissions, insecure temporary file creation, or race conditions in setuid binaries associated with printing services. Such flaws correspond closely to CWE-269 Improper Privilege Management and are frequently mapped to MITRE ATT&CK techniques like T1054 Indicator Removal on Host or T1078 Valid Accounts if the attacker leverages compromised credentials to exploit these weaknesses for persistent access.
Denial of service conditions arise when malformed inputs cause HPLIP components to crash, hang, or consume excessive resources, effectively disrupting printing services and potentially affecting other system processes that depend on them. This impacts availability, a core pillar of information security, and is categorized under CWE-400 Uncontrolled Resource Consumption. Attackers can exploit these flaws by sending specially crafted print jobs or network packets to the printer daemon, causing service interruptions without needing authentication in some configurations, which relates to ATT&CK technique T1499 Endpoint Denial of Service.
Information disclosure vulnerabilities allow attackers to read sensitive data from the local system, such as configuration files, user credentials stored in plaintext within certain legacy modes, or internal state information that reveals network topology and software versions. This is typically caused by CWE-200 Exposure of Sensitive Information to an Unauthorized Actor. The leakage of version details aids reconnaissance efforts for subsequent attacks, while access to local files can lead directly to credential theft if passwords are stored insecurely in printer configuration directories.
Unauthorized file modification poses a risk where attackers can overwrite or alter critical system files through HPLIP components that have write permissions to sensitive directories. This could involve modifying print spooler configurations, injecting malicious scripts into startup sequences via misconfigured hooks, or altering driver installation packages. These actions map to CWE-732 Incorrect Permission Assignment for Critical Resource and are consistent with ATT&CK tactics involving persistence mechanisms like T1546 Event Triggered Execution if the modified files trigger automated processes upon reboot or service restart.
Mitigation strategies must prioritize immediate patching of HPLIP to the latest stable version provided by HP, ensuring that all dependent packages in the Linux distribution are updated simultaneously to avoid dependency conflicts. Administrators should enforce strict file permissions on directories containing HPLIP configurations and spooler data, adhering to the principle of least privilege so that only authorized users can modify critical files. Network segmentation is also recommended to restrict access to printing services from untrusted networks, reducing the attack surface for remote exploitation attempts. Additionally, disabling unnecessary features within HPLIP such as web-based administration interfaces or network discovery protocols when not required minimizes potential entry points identified in these vulnerabilities.