A critical remote code execution flaw in the Mirasvit Cache Warmer Magento extension, identified as CVE-2026-45247, has been added to the U.S. Cybersecurity and Infrastructure Security Agency's Known Exploited Vulnerabilities catalog due to active exploitation in the wild. This vulnerability, with a CVSS score of 9.8, allows for deserialization of untrusted data, posing a significant threat to affected systems. The addition to the KEV catalog by CISA indicates a high level of concern and warrants immediate attention from administrators using the affected extension. As the vulnerability is being actively exploited, patching is considered a priority1. The high severity of this flaw and its active exploitation status make it a critical concern for practitioners, who should take immediate action to patch or mitigate the vulnerability to prevent potential attacks, as the exploitation status determines the urgency of the response.