Quick answers
- Is CVE-2026-77499 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-77499 being exploited in the wild.
- How severe is CVE-2026-77499?
- High severity, with a CVSS score of 7.5, published 8 September 2026.
- Which products and versions are affected?
- Microsoft Windows Server <UNKNOWN>.
- Is there a fix for CVE-2026-77499?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-77499 attacked?
- It is attacked over the network, in an operating system.
- Am I affected by CVE-2026-77499?
- Check whether you run Microsoft Windows Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A type confusion vulnerability exists in Windows DHCP Server where the application accesses a resource using an incompatible type, leading to memory corruption. The vulnerability can be exploited over the network by an unauthenticated attacker through specially crafted DHCP requests. Successful exploitation results in denial of service, crashing the DHCP service and rendering it unable to assign IP addresses. No authentication is required to trigger the vulnerability. A patch is available from Microsoft.
Affected products
- Microsoft Windows Server <UNKNOWN>
Timeline
- 2026-09-08: disclosed