CVE-2026-42899 — ASP.NET Core Denial of Service Vulnerability

Executive Summary

Loop with unreachable exit condition ('infinite loop') in ASP.NET Core allows an unauthorized attacker to deny service over a network.

Overview

7.5

CVSS HIGH

Important

MS Severity

Not Exploited

MS Exploit Status

Exploitation Unlikely

MS Exploit Likelihood

Category Denial of Service

Released May 12 2026

Last Updated May 12 2026

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.01177 — 0.63511 percentile

NVD CVSS 7.5 HIGH — matches MSRC

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C

ATTACK VECTOR

Network

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

None

INTEGRITY

None

AVAILABILITY

High

EXPLOIT CODE MATURITY

Unproven

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 6.5

EPSS Score

0.01177

probability of exploitation in the next 30 days

0.63511 percentile - updated 2026-06-21

View on FIRST.org

Affected Products

9 affected products

Product	KB Article	Severity	Impact	Restart Required
.NET 10.0 installed on Linux	`5093446 (Security Update)`	Important	Denial of Service	Maybe
.NET 10.0 installed on Mac OS	`5093446 (Security Update)`	Important	Denial of Service	Maybe
.NET 10.0 installed on Windows	`5093446 (Security Update)`	Important	Denial of Service	Maybe
.NET 8.0 installed on Linux	`5093447 (Security Update)`	Important	Denial of Service	Maybe
.NET 8.0 installed on Mac OS	`5093447 (Security Update)`	Important	Denial of Service	Maybe
.NET 8.0 installed on Windows	`5093447 (Security Update)`	Important	Denial of Service	Maybe
.NET 9.0 installed on Linux	`5093448 (Security Update)`	Important	Denial of Service	Maybe
.NET 9.0 installed on Mac OS	`5093448 (Security Update)`	Important	Denial of Service	Maybe
.NET 9.0 installed on Windows	`5093448 (Security Update)`	Important	Denial of Service	Maybe

Patches

3 patches

Article	Type	Restart
`5093446`	Security Update	Maybe
`5093447`	Security Update	Maybe
`5093448`	Security Update	Maybe

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

hamayanhamayan, Muhammad Abdul Rehman

References

MSRC Advisory MITRE NVD