CVE-2025-26508: HP FutureSmart 3 RCE Vulnerability

CVE-2025-26508 Overview

CVE-2025-26508 is a remote code execution (RCE) and elevation of privilege vulnerability affecting certain HP LaserJet Pro, HP LaserJet Enterprise, and HP LaserJet Managed Printers. The vulnerability is triggered when processing a maliciously crafted PostScript print job, allowing attackers to execute arbitrary code on vulnerable printer firmware.

This vulnerability stems from an out-of-bounds write (CWE-787) condition in the PostScript interpreter used by affected HP printer firmware. Attackers with network access to vulnerable printers can exploit this flaw to gain control over the device, potentially using it as a foothold for further network intrusion or to disrupt business operations.

Critical Impact

Remote attackers can achieve code execution and privilege escalation on enterprise printing infrastructure via specially crafted PostScript print jobs, potentially compromising network-connected devices without requiring authentication.

Affected Products

• HP FutureSmart 3 firmware
• HP FutureSmart 4 firmware
• HP FutureSmart 5 firmware
• HP LaserJet Pro printers (multiple models)
• HP LaserJet Enterprise printers (multiple models)
• HP LaserJet Managed printers (multiple models)

Discovery Timeline

• February 14, 2025 - CVE-2025-26508 published to NVD
• January 15, 2026 - Last updated in NVD database

Technical Details for CVE-2025-26508

Vulnerability Analysis

The vulnerability exists in the PostScript processing engine embedded in HP LaserJet printer firmware. When the printer processes a PostScript print job containing specially crafted commands, the firmware fails to properly validate input boundaries, resulting in an out-of-bounds write condition.

The attack vector is network-based, meaning exploitation can be achieved remotely without requiring physical access to the printer. While the attack complexity is high and requires certain preconditions to be met, successful exploitation does not require any user interaction or prior authentication. This makes the vulnerability particularly concerning for enterprise environments where printers are often directly accessible on corporate networks.

Successful exploitation allows an attacker to achieve high confidentiality impact through access to sensitive print data and printer configurations. Additionally, the vulnerability enables limited integrity and availability impacts, which could be leveraged for privilege escalation on the compromised device.

Root Cause

The root cause of CVE-2025-26508 is an out-of-bounds write vulnerability (CWE-787) in the PostScript interpreter. When processing specific PostScript operators or data structures, the firmware allocates a buffer with insufficient size or fails to properly bounds-check write operations. This allows attacker-controlled data to be written beyond the intended memory boundaries.

PostScript is a powerful page description language that includes programming capabilities. The PostScript interpreter in affected HP printers does not adequately sanitize or constrain certain operations, allowing malicious PostScript code to corrupt memory and potentially redirect execution flow to attacker-controlled code.

Attack Vector

The attack is executed by sending a specially crafted PostScript file to a vulnerable printer over the network. This can be accomplished through several methods:

1. Direct printing: Submitting a malicious print job directly to the printer's network interface (typically port 9100/JetDirect or IPP)
2. Print server exploitation: Routing malicious jobs through a Windows or CUPS print server
3. Spear-phishing: Convincing users to print a malicious document that contains embedded PostScript

The attacker crafts a PostScript document containing operators that trigger the out-of-bounds write condition. When the printer's PostScript interpreter processes this document, memory corruption occurs, allowing the attacker to gain code execution on the embedded processor running the printer firmware.

Once code execution is achieved, the attacker may be able to:

• Access or modify printer configurations
• Intercept or modify print jobs
• Use the printer as a pivot point for lateral movement within the network
• Cause denial of service conditions
• Establish persistent access through firmware modification

Detection Methods for CVE-2025-26508

Indicators of Compromise

• Unusual network traffic to printers on port 9100 (JetDirect) or 631 (IPP) from unexpected sources
• Abnormally large or malformed PostScript print jobs in print queue logs
• Printer firmware or configuration changes without administrator action
• Unexpected printer restarts or service interruptions
• Suspicious outbound network connections originating from printer IP addresses

Detection Strategies

• Monitor print job submissions for anomalous PostScript content or unusually large file sizes
• Implement network segmentation to isolate printers and enable granular traffic monitoring
• Deploy SIEM rules to alert on print traffic from unauthorized network segments
• Review printer access logs for connections from unexpected IP addresses or at unusual times

Monitoring Recommendations

• Enable logging on print servers and network devices handling print traffic
• Implement firmware version monitoring to detect unauthorized changes or missing patches
• Establish baseline network behavior for printer devices and alert on deviations
• Consider deploying network-based intrusion detection systems with signatures for PostScript-based attacks

How to Mitigate CVE-2025-26508

Immediate Actions Required

• Inventory all HP LaserJet Pro, Enterprise, and Managed printers in your environment to identify affected devices
• Prioritize patching for printers accessible from untrusted network segments
• Implement network access controls to restrict printer access to authorized hosts only
• Consider disabling PostScript processing temporarily if not required for business operations

Patch Information

HP has released firmware updates to address this vulnerability. Organizations should consult the HP Security Bulletin (HPSBPI04007) to identify the specific firmware versions required for their printer models.

Affected firmware includes HP FutureSmart versions 3, 4, and 5 across hundreds of printer models. Each model has a corresponding patched firmware version that addresses the PostScript processing vulnerability.

Administrators should:

1. Access the HP support portal to download the latest firmware for affected models
2. Test firmware updates in a non-production environment when possible
3. Deploy updates following organizational change management procedures
4. Verify successful firmware updates through printer configuration pages

Workarounds

• Isolate printers on a dedicated VLAN with restricted ingress/egress rules
• Disable PostScript processing and configure PCL-only printing if operationally feasible
• Implement firewall rules to block direct network access to printers from untrusted networks
• Configure printers to accept print jobs only from authorized print servers

# Example network segmentation using firewall rules
# Restrict printer access to print server only
iptables -A INPUT -s <print_server_ip> -d <printer_ip> -p tcp --dport 9100 -j ACCEPT
iptables -A INPUT -s <print_server_ip> -d <printer_ip> -p tcp --dport 631 -j ACCEPT
iptables -A INPUT -d <printer_ip> -p tcp --dport 9100 -j DROP
iptables -A INPUT -d <printer_ip> -p tcp --dport 631 -j DROP