CVE-2023-38180: Microsoft ASP.NET Core 2.1 · Denial of Service
Affects Microsoft ASP.NET Core 2.1Source CVE Database V5
Exploited in the wild · KEV due 30 Aug 2023 · 14% EPSS : apply the vendor's fix or mitigations to Microsoft ASP.NET Core 2.1 now.
Data as of 25 Oct 2026, 19:02 UTC
- KEV deadline
- US federal agencies must patch by this date; a sensible deadline for everyone else.
- EPSS
- 14.1% chance of exploitation in 30 days – higher than 96% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:CExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 8 Aug 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 1 day after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by microsoft
, 27 days before disclosure
CVE published
on cve.org
, t = 0
Added to CISA KEV (opens in a new tab)
exploitation confirmed
, 1 day after disclosure
KEV remediation due
US federal deadline
, 22 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
NuGetmicrosoft.aspnetcore.apppkg:nuget/microsoft.aspnetcore.appOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
.NET and Visual Studio Denial of Service Vulnerability
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2023-38180 (opens in a new tab)
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-38180 (opens in a new tab)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/CL2L4WE5QRT7WEXANYXSKSU43APC5N2V/ (opens in a new tab)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NWVZFKTLNMNKPZ755EMRYIA6GHFOWGKY/ (opens in a new tab)