What is CVE-2026-58599?

CVE-2026-58599 is a high-severity vulnerability in Microsoft Hevc Video Extensions, classified under Heap-based Buffer Overflow. CVSS score: 7.8/10. Published 2026-09-08.

How severe is CVE-2026-58599?

High severity. CVSS v3 base score is 7.8 out of 10.

Buffer overflow in Microsoft Hevc Video Extensions

CVE-2026-58599

Heap-based buffer overflow in Microsoft Windows Codecs Library allows an unauthorized attacker to execute code locally.

Vulnerability class: Buffer Overflow

Published 2026-09-08 · last modified 2026-10-01.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (39.5th percentile), scored 2026-10-24.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 39.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: -0.000

Affected products

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow

References

HEVC Video Extensions Remote Code Execution Vulnerability (vendor-advisory, Patch, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-58599?: CVE-2026-58599 is a high-severity vulnerability in Microsoft Hevc Video Extensions, classified under Heap-based Buffer Overflow. CVSS score: 7.8/10. Published 2026-09-08.
How severe is CVE-2026-58599?: High severity. CVSS v3 base score is 7.8 out of 10.