What is CVE-2018-8278?

CVE-2018-8278 is a medium-severity vulnerability in Microsoft Edge, classified under Authentication Bypass by Spoofing. CVSS score: 6.1/10. Published 2018-07-11.

How severe is CVE-2018-8278?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Vulnerability in Microsoft Edge

CVE-2018-8278

A spoofing vulnerability exists when Microsoft Edge improperly handles specific HTML content, aka "Microsoft Edge Spoofing Vulnerability." This affects Microsoft Edge.

Published 2018-07-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.069 (93.9th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 94th percentile — 93.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.064 · newest: 0.069 · change: +0.005

Affected products

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

Weakness classification (CWE)

CWE-290 — Authentication Bypass by Spoofing

References

www.securitytracker.com/id/1041255 (VDB Entry, Third Party Advisory, vdb-entry)
portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8278 (Patch, Vendor Advisory)
www.securityfocus.com/bid/104627 (VDB Entry, Third Party Advisory, vdb-entry)

Frequently asked questions

What is CVE-2018-8278?: CVE-2018-8278 is a medium-severity vulnerability in Microsoft Edge, classified under Authentication Bypass by Spoofing. CVSS score: 6.1/10. Published 2018-07-11.
How severe is CVE-2018-8278?: Medium severity. CVSS v3 base score is 6.1 out of 10.