CVE-2026-91098 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, which serves as the primary driver interface for many HP printers on Linux-based operating systems. The remediation effort targets a diverse range of potential attack vectors, including remote code execution, privilege escalation, denial of service, information disclosure, and unauthorized file modification. Each of these threat categories represents a distinct failure mode in the software’s security architecture, requiring targeted patches to restore secure operation for enterprise and individual users relying on HPLIP for networked printing services.
The potential for remote code execution constitutes one of the most severe risks associated with these vulnerabilities. If exploited successfully, an attacker could leverage specific flaws within the HPLIP components to execute arbitrary commands on the target system with the privileges of the application process. This capability fundamentally breaks the isolation between the user space and kernel space or other critical services, allowing malicious actors to install backdoors, exfiltrate data, or use the compromised machine as a pivot point for further network intrusion. Such vulnerabilities often stem from improper handling of input data in network-facing interfaces or printer communication protocols, where crafted packets can trigger buffer overflows or logic errors that result in code execution. This aligns with Common Weakness Enumeration categories such as CWE-120 Buffer Copy without Checking Size of Input and CWE-94 Improper Control of Generation of Code, highlighting the need for rigorous input validation and secure coding practices in network service daemons.
Privilege escalation represents another critical area of concern within this vulnerability set. HPLIP often requires elevated privileges to manage printer queues, access hardware devices, or modify system configurations. Flaws that allow a lower-privileged user to gain higher-level permissions can lead to complete compromise of the host operating system. For instance, if an application fails to properly enforce role-based access controls or contains logic errors in its privilege management routines, an attacker might exploit these weaknesses to bypass security restrictions and execute administrative commands. This type of vulnerability is frequently categorized under CWE-269 Improper Privilege Management or CWE-78 Improper Neutralization of Special Elements used in an OS Command Injection. The impact extends beyond the immediate user account, potentially granting control over system-wide settings, installed software, and sensitive files that are normally protected from standard users.
Denial of service vulnerabilities within HPLIP components can disrupt printing services and consume significant system resources such as CPU cycles or memory. By sending specially crafted requests or data streams to the affected services, an attacker could cause the application to crash, hang, or enter a loop that prevents legitimate users from accessing printer functionality. While often considered less severe than code execution flaws in terms of direct data theft, denial of service attacks can have substantial operational impacts on businesses reliant on continuous printing capabilities for daily operations. These issues typically arise from inadequate error handling when processing malformed inputs or resource exhaustion scenarios where the application fails to limit memory allocation or connection counts. Such weaknesses are commonly associated with CWE-400 Uncontrolled Resource Consumption and reflect gaps in robustness testing during the software development lifecycle.
Information disclosure vulnerabilities expose sensitive data that should remain confidential, potentially revealing system configurations, internal network topology, user credentials, or proprietary information stored on the host machine. In the context of HPLIP, this might involve leaking details about connected printers, driver versions, or even parts of the file system if path traversal flaws exist. Attackers can use this gathered intelligence to plan more sophisticated attacks against the target environment. These weaknesses are often linked to CWE-200 Exposure of Sensitive Information to an Unauthorized Actor and indicate insufficient sanitization of error messages or improper access controls on internal APIs used by the printing service. The exposure of such data aids adversaries in reconnaissance phases, as defined by MITRE ATT&CK techniques like T1087 Account Discovery or T1526 System Service Discovery, facilitating subsequent exploitation attempts.
Unauthorized file modification poses a direct threat to system integrity and stability. If an attacker can write to arbitrary locations on the filesystem through HPLIP components, they could alter configuration files, replace legitimate binaries with malicious versions, or corrupt critical data stores. This capability undermines trust in the operating environment and may lead to persistent compromise if not detected and remediated promptly. Such flaws are typically rooted in CWE-732 Incorrect Permission Assignment for Critical Resource or CWE-436 Interpretation of External Data, where the application fails to verify file paths or permissions before performing write operations. The ability to modify files allows attackers to establish persistence mechanisms or escalate privileges by tampering with system binaries and configuration scripts that are loaded during startup processes.
The remediation efforts undertaken by HP involve updating HPLIP packages across supported Linux distributions to patch these identified weaknesses. Users must apply the latest updates provided through their respective package managers to ensure protection against these threats. Given the interconnected nature of printing services within enterprise environments, it is crucial for system administrators to verify that all endpoints running vulnerable versions are updated promptly. Additionally, organizations should review their network segmentation strategies to limit exposure of HPLIP-related ports and services to untrusted networks. Implementing strict firewall rules and monitoring for anomalous behavior in print service logs can provide an additional layer of defense against exploitation attempts while patch management processes are completed.
Security best practices dictate that reliance on a single mitigation strategy is insufficient; therefore, a defense-in-depth approach is recommended. This includes keeping all system software up to date, disabling unused printing services if not required for business operations, and employing intrusion detection systems capable of identifying patterns associated with the aforementioned vulnerability types. Regular audits of file permissions and service configurations further reduce the attack surface available to potential adversaries. By addressing these vulnerabilities comprehensively, organizations can maintain the confidentiality, integrity, and availability of their IT infrastructure while continuing to utilize essential printing functionalities provided by HP hardware solutions.