What is CVE-2026-78455?

CVE-2026-78455 is a medium-severity vulnerability in Microsoft Windows 10 1607, classified under Out-of-bounds Read. CVSS score: 4.3/10. Published 2026-09-08.

How severe is CVE-2026-78455?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Out-of-bounds Read in Microsoft Windows 10 1607

CVE-2026-78455

Out-of-bounds read in Xbox allows an unauthorized attacker to disclose information with a physical attack.

Vulnerability class: Buffer Overflow

Published 2026-09-08 · last modified 2026-09-11.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.005 (43.6th percentile), scored 2026-10-24.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 43.6% 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-125 — Out-of-bounds Read

References

Xbox Information Disclosure Vulnerability (vendor-advisory, Patch, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-78455?: CVE-2026-78455 is a medium-severity vulnerability in Microsoft Windows 10 1607, classified under Out-of-bounds Read. CVSS score: 4.3/10. Published 2026-09-08.
How severe is CVE-2026-78455?: Medium severity. CVSS v3 base score is 4.3 out of 10.