What is CVE-2026-25667?

CVE-2026-25667 is a high-severity vulnerability in Microsoft .Net, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-03-19.

How severe is CVE-2026-25667?

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

Resource exhaustion in Microsoft .Net

CVE-2026-25667

ASP.NET Core Kestrel in Microsoft .NET 8.0 before 8.0.22 and .NET 9.0 before 9.0.11 allows a remote attacker to cause excessive CPU consumption by sending a crafted QUIC packet, because of an incorrect exit condition for HTTP/3 Encoder/Decoder stream processing.

Vulnerability class: DoS (Denial of Service)

EPSS: 0.030 (86.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

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

Affected products

Microsoft .Net
N/a — versions n/a

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

cve@mitre.org (Exploit, Third Party Advisory)
cve@mitre.org (Patch)
cve@mitre.org

Frequently asked questions

What is CVE-2026-25667?: CVE-2026-25667 is a high-severity vulnerability in Microsoft .Net, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-03-19.
How severe is CVE-2026-25667?: High severity. CVSS v3 base score is 7.5 out of 10.