Adobe Campaign Classic (ACC) is affected by a critical OS Command Injection vulnerability (CVE-2026-76197) classified as Improper Neutralization of Special Elements used in an OS Command. The vulnerability allows arbitrary code execution in the context of the current user. No user interaction is required for exploitation, making it particularly dangerous. The scope of the vulnerability is changed, indicating impact can extend beyond the vulnerable component. Adobe has published a security advisory (APSB26-134) to address this issue. The vulnerability carries a high criticality rating and poses significant risk to organizations using Adobe Campaign Classic.