CVE-2026-83869
9.8CriticalPublished 13 Oct 2026 · NVD status: Analyzed · AI triage by gemini-3.8-flash
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Impact
- Full C/I/A compromise
- Weakness
- CWE-191
Impact
Unauthenticated remote attackers can execute arbitrary code over the network on the DNS server. They only need network access to send malicious requests to the listening DNS service.
Root cause
An integer underflow (wraparound) flaw in the DNS Server service leads to memory corruption during packet processing.
Affected systems
Versions not listed — check the vendor advisory.
CVSS v3.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Fix & remediation
Install the relevant Microsoft security update from the vendor advisory immediately. If patching cannot happen right away, restrict network access to port 53 (UDP/TCP) to trusted endpoints only.
AI-suggested. Run it in staging first and check it against the vendor advisory. Why?
NVD description
Integer underflow (wrap or wraparound) in DNS Server allows an unauthorized attacker to execute code over a network.