cve 2026 55005

The cve 2026 55005 tag covers Microsoft’s July 2026 security update for an 8.8-rated remote code execution vulnerability in on-premises Exchange Server. The flaw is caused by a heap-based buffer overflow and can be exploited over the network without user interaction, although an attacker needs a valid low-privilege account. Successful exploitation could affect the confidentiality, integrity, and availability of an Exchange server. Microsoft classified the issue as Important rather than Critical because authentication is required. This tag provides focused information on the vulnerability, its Exchange Server impact, and the July 2026 builds that address it.