CVE-2026-45591
ASP.NET Core Denial of Service Vulnerability
No exploitation reported by the sources we read.
- Published2026-06-09
- Fixed in10.0.9 · 9.0.17 · 8.0.28
- WeaknessCWE-400 · CWE-770
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
Uncontrolled resource consumption in ASP.NET Core allows an unauthorized attacker to deny service over a network.
Timeline
dates in UTC- 2026-06-0917:17CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-45591?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-45591?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD · OSV| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 10.0 | ≥ 10.0.0, < 10.0.9 | 10.0.9 | NVD |
| 9.0 | ≥ 9.0.0, < 9.0.17 | 9.0.17 | NVD |
| 8.0 | ≥ 8.0.0, < 8.0.28 | 8.0.28 | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 10.0 | ≥ 10.0.0, < 10.0.9 | 10.0.9 | NVD · OSV |
| 9.0 | ≥ 9.0.0, < 9.0.17 | 9.0.17 | NVD |
| 8.0 | ≥ 8.0.0, < 8.0.28 | 8.0.28 | NVD · OSV |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 18.6 | ≥ 18.6.0, < 18.6.3 | 18.6.3 | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Distribution builds and vendor advisories
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Packages
- dotnetAlmaLinux:8all versions · fixed in 10.0.109-1.el8_10and 5 other packages
- dotnet-hostAlmaLinux:10all versions · fixed in 10.0.9-1.el10_2and 8 other packages
- dotnet-hostAlmaLinux:9all versions · fixed in 10.0.9-1.el9_8and 8 other packages
- dotnet-hostAlmaLinux:8all versions · fixed in 10.0.9-1.el8_10and 8 other packages
- dotnet-hostfxr-8.0AlmaLinux:10all versions · fixed in 8.0.28-1.el10_2and 7 other packages
- dotnet-hostfxr-8.0AlmaLinux:9all versions · fixed in 8.0.28-1.el9_8and 7 other packages
- dotnet-hostfxr-8.0AlmaLinux:8all versions · fixed in 8.0.28-1.el8_10and 7 other packages
- dotnet-hostfxr-9.0AlmaLinux:10all versions · fixed in 9.0.17-1.el10_2and 7 other packages
10 more package ranges on OSV.dev
Vendor advisories
dotnet: ASP.NET Core: Denial of Service via uncontrolled resource consumption
Red Hat Security Advisory: .NET 9.0 security update
Red Hat Security Advisory: .NET 8.0 security update
Red Hat Security Advisory: .NET 8.0 security update
Red Hat Security Advisory: .NET 9.0 security update
Red Hat Security Advisory: .NET 8.0 security update
12 more advisories
Fix
- Update ASP.NET Core to 10.0.9 · 9.0.17 · 8.0.28
- Vendor fix Red Hat Product Security RHSA-2026:28051 · 119 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
- Vendor fix Red Hat Product Security RHSA-2026:26994 · 9 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
- Workaround from the vendor Red Hat Product Security RHSA-2026:28051 · 119 productsRed Hat is not aware of a practical temporary workaround that fully mitigates this issue or meets Red Hat Product Security's standards for usability, deployment, applicability, or stability. Customers are advised to apply the relevant security updates when they become available.
Advisories and patches
- msrc.microsoft.comVendor Advisory
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
- NVDCVE recordread 2026-10-23
- CISA-ADPSSVC decisionnone2026-06-10
- OpenCVESSVC decisionnone—
- CNACVSS 3.17.5read 2026-10-23
- CNAweakness (CWE)CWE-400, CWE-770read 2026-10-23
- FIRST EPSSEPSS score2.4 %2026-10-22
- OSVaffected packages—
- Microsoft MSRCadvisory—
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Published
- 2026-06-09
- Last Modified
- 2026-07-23
- NVD status
- Modified
- MSRC Title
- ASP.NET Core Denial of Service Vulnerability
Frequently asked questions
What is CVE-2026-45591?
Is CVE-2026-45591 actively exploited?
What is the CVSS score for CVE-2026-45591?
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.