(0Day) FontForge SFD File Parsing Improper Validation of Array Index Remote Code Execution Vulnerability
Vulnerability Details
This vulnerability allows remote attackers to execute arbitrary code on affected installations of FontForge. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the parsing of SFD files. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated array. An attacker can leverage this vulnerability to execute code in the context of the current user.
Additional Details
12/12/25 - ZDI submitted the reports to the vendor via third-party platform
12/13/25 - ZDI reached out to the vendor’s GitHub account
12/13/25 – the vendor rejected the vulnerability, stating that only pull requests that include the required fixes will be considered
12/15/25 – ZDI notified the vendor of the intention to publish the case as a 0-day advisory on 12/29/25
-- Mitigation: Given the nature of the vulnerability, the only salient mitigation strategy is to restrict interaction with the product
Disclosure Timeline
- 2025-12-12 - Vulnerability reported to vendor
- 2025-12-29 - Coordinated public release of advisory
- 2026-01-08 - Advisory Updated
Credit
Anonymous
