CVE Almanac
← All CVEs

CVE-2026-45584

HIGH 8.1

Published 2026-05-20 · Last modified 2026-06-19

Heap-based buffer overflow in Microsoft Defender allows an unauthorized attacker to execute code over a network.

ELEVATED IMPACT

Severe if exploited (CVSS 8.1), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.9%chance of exploitation in 30 days · 54th percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

8.1CVSS 3.1 · HIGH

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityHigh

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ✓User interaction: No user interaction needed
  • ⚠Complexity: Needs a race window or specific setup

✓ lowers the bar for an attacker · ⚠ raises it

Affected

Vendors Microsoft

Products Microsoft Malware Protection Engine

Weakness (CWE)

  • CWE-122

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

References

Patches & mitigations

Sources: NVD · CVE.org · EPSS