What is CVE-2026-70179?

CVE-2026-70179 is a high-severity vulnerability in Microsoft Microsoft.aspnetcore.authentication.negotiate, classified under Authentication Bypass by Spoofing. CVSS score: 7.5/10. Published 2026-10-13.

How severe is CVE-2026-70179?

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

Vulnerability in Microsoft Microsoft.aspnetcore.authentication.negotiate

CVE-2026-70179

Authentication bypass by spoofing in ASP.NET Core allows an authorized attacker to elevate privileges over a network.

Published 2026-10-13 · last modified 2026-10-13.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

CWE-290 — Authentication Bypass by Spoofing

References

ASP.NET Core Elevation of Privilege Vulnerability (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-70179?: CVE-2026-70179 is a high-severity vulnerability in Microsoft Microsoft.aspnetcore.authentication.negotiate, classified under Authentication Bypass by Spoofing. CVSS score: 7.5/10. Published 2026-10-13.
How severe is CVE-2026-70179?: High severity. CVSS v3 base score is 7.5 out of 10.