Executive Summary:
A high-severity vulnerability has been identified in multiple FontForge products, which could allow an attacker to take full control of an affected system. The flaw is triggered when a user opens a specially crafted font (SFD) file, leading to a heap-based buffer overflow that enables remote code execution. This could result in a complete system compromise, data theft, or the installation of malware.

Vulnerability Details

CVE-ID: CVE-2025-15275

Affected Software: FontForge Multiple Products

Affected Versions: See vendor advisory for specific affected versions

Vulnerability: This vulnerability is a heap-based buffer overflow that occurs within the file parsing component of FontForge when processing SFD (Spline Font Database) files. An attacker can craft a malicious SFD file with specific data that exceeds the allocated buffer size in the application's memory. When a victim opens this malicious file, the application attempts to write the oversized data, causing it to overflow the buffer and corrupt adjacent memory, which can be leveraged by the attacker to execute arbitrary code with the same permissions as the user running the software.

Business Impact

This vulnerability is rated as High severity with a CVSS score of 8.8, posing a significant risk to the organization. Successful exploitation could lead to a complete compromise of the affected workstation or server, allowing an attacker to steal sensitive data, install persistent malware such as ransomware or spyware, or use the compromised system as a foothold to move laterally within the network. The potential consequences include loss of intellectual property, operational disruption, financial loss, and reputational damage.

Remediation Plan

Immediate Action: Apply the security patches released by FontForge to all affected systems immediately, prioritizing any internet-facing systems or those used to process files from untrusted sources. Following patching, monitor for any signs of exploitation attempts by reviewing application and system access logs for anomalous activity.

Proactive Monitoring: Implement enhanced monitoring on systems running FontForge. Look for application crashes, unexpected process creation originating from the FontForge executable, or unusual outbound network traffic from affected endpoints. Endpoint Detection and Response (EDR) solutions should be configured to alert on suspicious behavior chains involving FontForge.

Compensating Controls: If immediate patching is not feasible, implement the following controls to reduce risk:

• User Awareness: Instruct users to avoid opening SFD files from untrusted or unknown sources, such as email attachments or web downloads.
• Sandboxing: Run FontForge in a restricted, sandboxed environment to contain any potential exploitation and limit its access to the underlying operating system.
• Principle of Least Privilege: Ensure the application is run by users with non-administrative privileges to limit the impact of a successful exploit.

Exploitation Status

Public Exploit Available: false

Analyst Notes: As of January 1, 2026, there are no known public exploits or active campaigns targeting this vulnerability. However, due to the high severity and the potential for remote code execution, it is highly likely that threat actors will develop exploits. The attack vector requires user interaction, making it a suitable payload for targeted phishing campaigns.

Analyst Recommendation

Given the high CVSS score of 8.8, this vulnerability requires immediate attention. We strongly recommend that organizations prioritize the deployment of the vendor-supplied patches to all vulnerable systems without delay. Although this CVE is not currently listed on the CISA KEV catalog, its critical nature warrants urgent remediation to prevent potential system compromise and data breaches. If patching is delayed, the compensating controls listed above should be implemented as an interim measure.

Executive Summary:
A critical vulnerability has been discovered in FontForge software, identified as CVE-2025-15274. This flaw allows an attacker to take full control of a user's computer by tricking them into opening a specially crafted font file. Successful exploitation could lead to data theft, malware installation, or further compromise of the organization's network.

Vulnerability Details

CVE-ID: CVE-2025-15274

Affected Software: FontForge Multiple Products

Affected Versions: See vendor advisory for specific affected versions

Vulnerability: This is a heap-based buffer overflow vulnerability that occurs during the parsing of Spline Font Database (.sfd) files. An attacker can create a malicious .sfd file with specific data that, when opened by a vulnerable version of FontForge, causes the application to write data beyond the intended memory buffer. This memory corruption can be leveraged by the attacker to overwrite critical program instructions and execute arbitrary code on the victim's system with the same privileges as the user running the application.

Business Impact

This is a High severity vulnerability with a CVSS score of 8.8. Successful exploitation grants an attacker Remote Code Execution (RCE) capabilities on the affected system. The potential consequences include the installation of malware such as ransomware or spyware, theft of sensitive intellectual property or personal data, and unauthorized access to the corporate network. If an attacker gains a foothold, they can use the compromised machine to move laterally and attack other internal systems, leading to a wider data breach, significant financial loss, and reputational damage.

Remediation Plan

Immediate Action: Apply security patches provided by FontForge immediately to all systems where the software is installed, prioritizing any internet-facing or automated systems that may process .sfd files. After patching, monitor systems for any signs of exploitation attempts by reviewing application and system logs for unexpected crashes or behavior related to FontForge processes.

Proactive Monitoring: Implement enhanced monitoring to detect potential exploitation. Look for FontForge application crashes in system event logs, monitor for unusual child processes spawned by FontForge, and inspect network traffic for unexpected outbound connections from workstations running the software. Endpoint Detection and Response (EDR) solutions should be configured to alert on suspicious file creation or process execution originating from FontForge.

Compensating Controls: If immediate patching is not feasible, implement compensating controls to reduce risk. Restrict the opening of .sfd files from untrusted sources, such as email attachments or web downloads. Use application control software to prevent FontForge from executing unknown child processes. Consider running FontForge in a sandboxed or virtualized environment to contain the impact of a potential compromise.

Exploitation Status

Public Exploit Available: false

Analyst Notes: As of January 1, 2026, there are no known public exploits or active malicious campaigns targeting this vulnerability. However, due to the high severity and the potential for reliable exploitation leading to RCE, it is highly probable that proof-of-concept code will be developed and released by security researchers or threat actors. The vulnerability is not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog, but this status should be monitored closely.

Analyst Recommendation

Given the high severity (CVSS 8.8) and the risk of remote code execution, this vulnerability poses a significant threat to the organization. We strongly recommend that all vulnerable instances of FontForge are patched immediately, following the principle of "patch, then monitor." While this CVE is not yet on the CISA KEV list, its critical nature demands that it be treated with the highest priority. Organizations should assume that threat actors will actively work to develop exploits for this vulnerability and must act preemptively to mitigate the risk.

Executive Summary:
A critical remote code execution vulnerability has been identified in multiple FontForge products. An attacker could exploit this flaw by tricking a user into opening a specially crafted PFB font file, which could allow the attacker to take full control of the affected system, leading to data theft, malware installation, or further network intrusion.

Vulnerability Details

CVE-ID: CVE-2025-15273

Affected Software: FontForge Multiple Products

Affected Versions: See vendor advisory for specific affected versions

Vulnerability: This vulnerability is a stack-based buffer overflow that occurs within the file parsing component of FontForge when processing PFB (PostScript Font Binary) files. An attacker can create a malicious PFB file containing data that exceeds the size of the buffer allocated for it on the program's stack. When FontForge attempts to parse this file, the excess data overwrites adjacent memory on the stack, which can include the function's return address. By controlling this overwritten data, an attacker can redirect the program's execution flow to malicious code embedded within the file, resulting in remote code execution (RCE) in the context of the user running FontForge.

Business Impact

This vulnerability presents a significant risk to the organization, rated as High severity with a CVSS score of 8.8. Successful exploitation allows an attacker to execute arbitrary code on an employee's workstation. This could lead to the compromise of sensitive corporate data, theft of user credentials, deployment of ransomware, or the use of the compromised machine as a beachhead to launch further attacks against the internal network. The primary risk is to users who work with external or untrusted font files, such as graphic designers or marketing personnel, potentially leading to a breach of confidentiality, integrity, and availability.

Remediation Plan

Immediate Action: The primary remediation is to apply the security patches released by the vendor to all affected systems. Patching should be prioritized for internet-facing systems and workstations used by employees who are likely to handle files from external sources. Following patching, review system and application logs for any signs of crashes or anomalous behavior related to FontForge.

Proactive Monitoring: Implement enhanced monitoring on endpoints running FontForge. Look for suspicious child processes being spawned by the FontForge application (e.g., cmd.exe, powershell.exe, /bin/sh). Monitor for unusual network connections originating from the FontForge process to external IP addresses. Security teams should create detection rules in SIEM or EDR solutions to alert on FontForge application crashes followed by suspicious system activity.

Compensating Controls: If immediate patching is not feasible, implement the following compensating controls to reduce the risk of exploitation:

• User Awareness: Instruct users, especially those in design-related roles, not to open or install PFB font files from untrusted sources, such as suspicious websites or unsolicited emails.
• Application Sandboxing: Run FontForge within a sandboxed or virtualized environment to contain any potential exploit and prevent it from affecting the host operating system.
• Endpoint Security: Ensure Endpoint Detection and Response (EDR) and antivirus solutions are up-to-date and configured to monitor for memory corruption exploitation techniques and anomalous process behavior.

Exploitation Status

Public Exploit Available: false

Analyst Notes: As of the publication date of December 31, 2025, there are no known public proof-of-concept exploits or active exploitation campaigns targeting this vulnerability. However, stack-based buffer overflows are a well-understood vulnerability class, and it is highly likely that threat actors will develop exploits. Organizations should operate under the assumption that an exploit will become available soon.

Analyst Recommendation

Given the high CVSS score of 8.8 and the potential for complete system compromise, this vulnerability requires immediate attention. The primary recommendation is to apply the vendor-supplied patches across all affected assets without delay. Although this vulnerability is not currently listed on the CISA KEV catalog, its high severity and the straightforward nature of the attack vector warrant urgent remediation. If patching is delayed, the compensating controls listed above should be implemented as an interim measure to mitigate risk.