CVE-2026-91101 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.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
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 effort underscores the critical nature of these defects in a widely deployed printing subsystem often running with elevated privileges or interacting directly with hardware interfaces.
The potential for remote code execution represents one of the most critical risks associated with these vulnerabilities. If an attacker can trigger specific input handling routines within HPLIP components, they may execute arbitrary commands on the target system. This capability aligns with CWE-94 Improper Control of Generation of Code or Command and is frequently mapped to MITRE ATT&CK techniques such as T1059 Command and Scripting Interpreter or T1203 Exploitation for Client Execution. The impact extends beyond mere access, allowing attackers to establish persistent footholds within the network infrastructure by leveraging compromised printing services as a pivot point for further lateral movement.
Privilege escalation remains another primary concern highlighted in these findings. HPLIP components often operate with root-level permissions or interact with system resources that require high-privilege contexts. Flaws in how these components validate input or manage state can allow lower-privileged users to escalate their access rights, effectively bypassing standard security controls. This scenario corresponds closely to CWE-269 Improper Privilege Management and is often associated with ATT&CK technique T1078 Valid Accounts if the escalation relies on credential manipulation, or T1548 Abuse Elevation Control Mechanism if it involves exploiting misconfigured access control lists or sudo rules inherent in the printing subsystem.
Denial of service vulnerabilities present a risk to system availability and operational continuity. By sending malformed data or triggering specific resource exhaustion conditions within HPLIP modules, an attacker could crash services or consume excessive CPU and memory resources, rendering the printer server unusable for legitimate users. This type of flaw is categorized under CWE-400 Uncontrolled Resource Consumption and maps directly to ATT&CK technique T1499 Endpoint Denial of Service. In enterprise environments where printing infrastructure is critical to daily operations, such disruptions can lead to significant productivity losses and operational downtime.
Information disclosure vulnerabilities expose sensitive data that should remain confidential within the system boundary. These flaws may allow attackers to read files outside their intended scope or extract internal state information through error messages or memory leaks. This aligns with CWE-200 Exposure of Sensitive Information to an Unauthorized Actor and is often linked to ATT&CK technique T1005 Data from Local System. The leakage of system configuration details, user credentials stored in plaintext within certain HPLIP configurations, or internal network topology information can facilitate further attacks against the broader infrastructure.
Unauthorized file modification capabilities allow attackers to alter critical system files or printer configuration settings without proper authorization. This undermines the integrity of the operating system and printing services, potentially leading to persistent backdoors or misconfigured security policies. Such flaws are classified under CWE-732 Incorrect Permission Assignment for Critical Resource and correspond to ATT&CK techniques like T1099 Tool Binary Proxy Execution if used to replace legitimate binaries, or T1564 Hidden Files and Directories if the modifications involve concealing malicious artifacts. The ability to modify files without detection poses a severe threat to long-term system security posture.
Mitigation strategies must prioritize immediate patching of all affected HPLIP components using vendor-provided updates. Organizations should verify that their printing infrastructure is running the latest stable version of HP Linux Imaging and Printing software, as these releases contain the necessary code fixes for the identified flaws. Additionally, implementing strict network segmentation to limit access to printing services can reduce the attack surface available to potential adversaries. Applying principle of least privilege by ensuring HPLIP processes run with minimal required permissions further mitigates the risk of privilege escalation and unauthorized file modifications. Regular auditing of system logs for anomalous activity related to printing subsystems is also recommended to detect any attempted exploitation in real time.