CVE-2026-77907

CVE-2026-77907 is a heap-based buffer overflow (CWE-122) in Microsoft Visual Studio that is reachable over the network by an unauthorized attacker; the CVSS vector (AV:N/PR:N/UI:R) indicates no credentials or privileges are needed, but user interaction is required, suggesting the victim must interact with attacker-influenced content such as a crafted file, solution, or data stream. Successful exploitation yields arbitrary code execution with high impact on confidentiality, integrity, and availability, within the privileges of the affected Visual Studio process (scope unchanged). Developers and development organizations running the affected Visual Studio releases are exposed; the source data does not specify which versions or editions are affected, so the official MSRC advisory should be consulted for scoping. Exploitation is currently quiet: there is no known in-the-wild exploitation, no public proof of concept, and the flaw is not in CISA KEV, with EPSS estimating only about a 0.6% probability of exploitation in the next 30 days (45th percentile).

What to do: Track the MSRC advisory for CVE-2026-77907 and apply Microsoft's Visual Studio security update to all developer workstations and build machines as soon as the affected-version list and patched builds are published (versions are not specified in the available data). Because exploitation requires user interaction, meanwhile caution developers against opening untrusted solutions, projects, or files in Visual Studio. No workaround is documented and there is no KEV deadline, so treat this as a standard-priority patch rather than an emergency, but verify remediation on CI/CD hosts where Visual Studio runs unattended.