CVE-2025-26507: HP FutureSmart 3 RCE Vulnerability

CVE-2025-26507 Overview

CVE-2025-26507 is a stack-based buffer overflow vulnerability affecting certain HP LaserJet Pro, HP LaserJet Enterprise, and HP LaserJet Managed Printers. The vulnerability exists in the PostScript print job processing functionality, which may allow attackers to achieve Remote Code Execution (RCE) and Elevation of Privilege when a vulnerable device processes a maliciously crafted PostScript print job.

PostScript is a page description language commonly used in the printing industry. When printers process PostScript jobs, they interpret and execute the embedded commands. This vulnerability exploits improper input validation in the PostScript interpreter, enabling an attacker to overflow stack buffers and potentially execute arbitrary code on the affected printer's embedded system.

Critical Impact

Successful exploitation could allow attackers to execute arbitrary code on vulnerable HP printers, potentially enabling network pivoting, data exfiltration of printed documents, or establishing persistent access within enterprise environments.

Affected Products

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

Discovery Timeline

• February 14, 2025 - CVE-2025-26507 published to NVD
• January 15, 2026 - Last updated in NVD database

Technical Details for CVE-2025-26507

Vulnerability Analysis

This vulnerability is classified as CWE-121 (Stack-based Buffer Overflow), which occurs when a program writes more data to a stack-allocated buffer than it can hold. In the context of HP LaserJet printers, the PostScript interpreter fails to properly validate the size of certain input data during print job processing, allowing attackers to overflow stack buffers.

The attack requires network access to the vulnerable printer and involves sending a specially crafted PostScript print job. While the complexity of exploitation is high due to the need for precise payload construction, no user interaction or prior authentication is required, making it potentially exploitable by any network-accessible attacker.

Enterprise printers are particularly valuable targets because they often process sensitive documents, reside on internal networks with access to other systems, and rarely receive the same security monitoring as traditional endpoints. A compromised printer can serve as a foothold for lateral movement within corporate networks.

Root Cause

The root cause is a stack-based buffer overflow (CWE-121) in the PostScript interpreter component of the affected HP printer firmware. When processing PostScript commands, the interpreter allocates fixed-size buffers on the stack to store intermediate data. Maliciously crafted PostScript jobs can include commands that cause the interpreter to write beyond these buffer boundaries, corrupting adjacent stack memory.

This memory corruption can overwrite return addresses and other critical stack data, enabling attackers to redirect program execution to attacker-controlled code. The vulnerability affects multiple firmware versions across the FutureSmart 3, FutureSmart 4, and FutureSmart 5 firmware families.

Attack Vector

The attack is network-based and targets the print job processing pipeline. An attacker can exploit this vulnerability by:

1. Identifying a vulnerable HP LaserJet printer accessible on the network
2. Crafting a malicious PostScript print job containing overflow triggers
3. Submitting the print job to the target printer via standard printing protocols (Port 9100/JetDirect, IPP, or LPR/LPD)
4. The PostScript interpreter processes the job and triggers the buffer overflow
5. Arbitrary code execution occurs on the printer's embedded processor

The vulnerability can be exploited remotely without authentication, though exploitation requires careful payload construction due to the embedded nature of printer firmware. The PostScript language's Turing-complete nature provides attackers with significant flexibility in crafting exploitation payloads.

Detection Methods for CVE-2025-26507

Indicators of Compromise

• Unusual network traffic patterns to printers on standard printing ports (9100, 631, 515)
• Printers exhibiting unexpected behavior such as reboots, configuration changes, or connectivity issues after processing print jobs
• Anomalous outbound network connections originating from printer IP addresses
• Print queue failures or errors when processing specific jobs followed by printer restarts

Detection Strategies

• Implement network monitoring to detect large or malformed PostScript jobs being sent to printers
• Deploy intrusion detection signatures to identify known PostScript exploitation patterns
• Monitor printer firmware versions across the fleet to identify unpatched devices
• Enable and review printer event logs for processing errors or unexpected restarts

Monitoring Recommendations

• Segment printers on dedicated network VLANs with restricted access to critical systems
• Implement network access controls limiting which hosts can submit print jobs
• Configure printer management systems to alert on firmware version discrepancies
• Enable syslog forwarding from enterprise printers to centralized SIEM systems for analysis

How to Mitigate CVE-2025-26507

Immediate Actions Required

• Review the HP Security Bulletin (HPSBPI04007) for model-specific patch availability
• Inventory all HP LaserJet Pro, Enterprise, and Managed printers in your environment
• Prioritize patching printers that are network-accessible or process sensitive documents
• Implement network segmentation to restrict direct access to printers from untrusted networks

Patch Information

HP has released firmware updates to address this vulnerability. Administrators should consult the HP Security Bulletin (HPSBPI04007) for specific firmware versions that contain the fix.

The security bulletin provides detailed information about which firmware versions address CVE-2025-26507 for each affected product model. Updates are available for devices running FutureSmart 3, FutureSmart 4, and FutureSmart 5 firmware.

Firmware updates can typically be applied through:

• HP Web Jetadmin for enterprise fleet management
• HP Smart Device Services
• Direct firmware upload via the printer's Embedded Web Server (EWS)
• USB firmware update procedures

Workarounds

• Disable PostScript processing if not required and use PCL or other print languages instead
• Implement strict network access controls to limit which hosts can send print jobs to vulnerable devices
• Place printers behind firewalls or on isolated network segments with no direct internet access
• Monitor printing protocols for anomalous activity patterns until patches can be deployed

# Example network segmentation approach using firewall rules
# Restrict print job submissions to authorized print servers only

# Allow print traffic only from designated print server
iptables -A INPUT -p tcp -s 192.168.10.5 --dport 9100 -j ACCEPT
iptables -A INPUT -p tcp -s 192.168.10.5 --dport 631 -j ACCEPT
iptables -A INPUT -p tcp --dport 9100 -j DROP
iptables -A INPUT -p tcp --dport 631 -j DROP

# Block outbound connections from printer subnet
iptables -A FORWARD -s 192.168.20.0/24 -d 0.0.0.0/0 -j DROP