What is CVE-2018-8377?

CVE-2018-8377 is a high-severity vulnerability in Microsoft Edge, classified under Out-of-bounds Write. CVSS score: 7.5/10. Published 2018-08-15.

How severe is CVE-2018-8377?

High severity. CVSS v3 base score is 7.5 out of 10.

Buffer overflow in Microsoft Edge

CVE-2018-8377

A remote code execution vulnerability exists when Microsoft Edge improperly accesses objects in memory, aka "Microsoft Edge Memory Corruption Vulnerability." This affects Microsoft Edge. This CVE ID is unique from CVE-2018-8387.

Vulnerability class: Buffer Overflow

Published 2018-08-15 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.095 (95.3th percentile), scored 2026-10-03.

Low probability of exploitation in the next 30 days, but still tracked. 95th percentile — 95.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.095 · newest: 0.095 · change: 0.000

Affected products

Microsoft Edge
Microsoft Edge — versions Windows 10 Version 1709 for 32-bit Systems, Windows 10 Version 1709 for x64-based Systems, Windows 10 Version 1803 for 32-bit Systems
Microsoft Windows 10 — versions 1709, 1803

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8377 (Patch, Vendor Advisory)
www.securityfocus.com/bid/105020 (VDB Entry, Third Party Advisory, vdb-entry)

Frequently asked questions

What is CVE-2018-8377?: CVE-2018-8377 is a high-severity vulnerability in Microsoft Edge, classified under Out-of-bounds Write. CVSS score: 7.5/10. Published 2018-08-15.
How severe is CVE-2018-8377?: High severity. CVSS v3 base score is 7.5 out of 10.