CVE-2025-6644: pdf-xchange pdf-tools Use After Free

Vulnerability summary

CVE-2025-6644 is a high (CVSS 7.8) Use After Free vulnerability in pdf-xchange pdf-tools. EPSS estimates a 0.29% chance of exploitation in the next 30 days, higher than 19.9% of scored vulnerabilities.

Timeline

1. 25-06-2025
   PublishedVulnerability first disclosed.
2. 26-06-2025
   Last modifiedVulnerability information updated.

Description

PDF-XChange Editor U3D File Parsing Use-After-Free Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of PDF-XChange Editor. 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 U3D files. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-26536.

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.