CVE-2026-23656

CVE-2026-23656 is a medium-severity spoofing vulnerability in Microsoft Windows App Installer, rated 5.9 CVSS, caused by insufficient verification of data authenticity. An unauthenticated attacker can exploit this over a network to perform spoofing, though it requires high attack complexity. The potential impact is high integrity compromise, with no confidentiality or availability impact. There is currently no evidence of active exploitation, nor are public exploit modules available. While not on the CISA KEV catalog, it has received limited discussion and media coverage from security researchers.