CVE-2026-2889 is a use-after-free vulnerability found in the CCExtractor software, a tool widely used for extracting closed captions from video files. The vulnerability resides in the processmp4 function within the source file src/lib_ccx/mp4.c. Specifically, improper handling of memory during MP4 processing leads to a use-after-free condition, where the program attempts to access memory after it has been freed. This can cause undefined behavior including crashes or potential execution of arbitrary code. The attack vector requires local access with limited privileges, meaning an attacker must have some level of access to the host system to exploit the flaw. No user interaction or authentication is necessary beyond local presence. The vulnerability affects all CCExtractor versions from 0.96.0 through 0.96.5. The developers have addressed the issue in version 0.96.6 with a patch (commit fd7271bae238ccb3ae8a71304ea64f0886324925). Although the exploit code is publicly available, there are no confirmed reports of exploitation in the wild. The CVSS v4.0 base score is 4.8, reflecting a medium severity level due to the local attack vector and limited impact scope.

The primary impact of this vulnerability is potential memory corruption on systems running vulnerable versions of CCExtractor. This could lead to application crashes, denial of service, or in some cases, privilege escalation or arbitrary code execution if an attacker can carefully craft malicious MP4 files and execute them locally. Since exploitation requires local access, the risk is primarily to environments where untrusted users have local system access or where CCExtractor is run in multi-user or shared environments. Organizations relying on CCExtractor for media processing or caption extraction could face service disruptions or compromise of system integrity if the vulnerability is exploited. The medium severity score reflects the moderate risk, but the availability of public exploit code increases the urgency to patch. The vulnerability does not affect confidentiality or integrity directly unless combined with other attack vectors.

To mitigate CVE-2026-2889, organizations should upgrade CCExtractor to version 0.96.6 or later, which contains the official patch fixing the use-after-free issue. If immediate upgrade is not feasible, restrict local access to systems running vulnerable versions to trusted users only, minimizing the risk of exploitation. Employ application sandboxing or containerization to limit the impact of potential exploitation. Monitor system logs and application behavior for crashes or anomalies related to MP4 processing. Additionally, implement strict file validation and scanning of media files before processing with CCExtractor to detect malformed or malicious inputs. Regularly review and apply security updates for all media processing tools to reduce attack surface.