CVE-2026-47300
published 2026-07-14CVE-2026-47300: Incorrect implementation of authentication algorithm in ASP.NET Core allows an authorized attacker to elevate privileges over a network.
PriorityP260high8.8CVSS 3.1
AVNACLPRLUINSUCHIHAH
EPSS
0.53%
42.9th percentile
Incorrect implementation of authentication algorithm in ASP.NET Core allows an authorized attacker to elevate privileges over a network.
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | microsoft_visual_studio_2022_version_17.12 | >= 17.12.0 < 17.12.22 | 17.12.22 |
| microsoft | microsoft_visual_studio_2022_version_17.14 | >= 17.14.0 < 17.14.36 | 17.14.36 |
| microsoft | microsoft_visual_studio_2026_version_18.7 | >= 18.0 < 18.7.4 | 18.7.4 |
| microsoft | net | >= 10.0.0 < 10.0.6 | 10.0.6 |
| microsoft | net | >= 8.0.0 < 8.0.29 | 8.0.29 |
| microsoft | net | >= 9.0.0 < 9.0.18 | 9.0.18 |
| microsoft | net_10.0 | >= 10.0.0 < 10.0.10 | 10.0.10 |
| microsoft | net_8.0 | >= 8.0.0 < 8.0.29 | 8.0.29 |
| microsoft | net_9.0 | >= 9.0.0 < 9.0.18 | 9.0.18 |
| microsoft | visual_studio_2022 | >= 17.12.0 < 17.12.22 | 17.12.22 |
| microsoft | visual_studio_2022 | >= 17.14.0 < 17.14.36 | 17.14.36 |
| microsoft | visual_studio_2026 | >= 18.7.0 < 18.7.4 | 18.7.4 |
| ubuntu | dotnet10 | — | — |
| ubuntu | dotnet8 | — | — |
Detection & IOCsextracted from sources · hover to see the quote
- →CVE-2026-47300 affects ASP.NET Core across multiple .NET versions (8.0, 9.0, 10.0); monitor for privilege escalation activity originating from authenticated network sessions in ASP.NET Core applications ↗
- ·Affected packages span dotnet8.0, dotnet9.0, and dotnet10.0 on Fedora; package maintainers must verify whether the flaw affects their specific package before patching ↗
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
ghsa8.8HIGH
vendor_redhat8.8HIGH
vendor_ubuntu8.8HIGH
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Ubuntu
.NET vulnerabilities
vendor_ubuntu·2026-07-15·CVSS 8.8
CVE-2026-57108 [HIGH] .NET vulnerabilities
Title: .NET vulnerabilities
Summary: Several security issues were fixed in .NET.
Artur Stetsko discovered that the .NET did not properly validate
authentication data. An attacker could possibly use this issue to elevate
privileges. (CVE-2026-47300)
Levi Broderick discovered that .NET did not properly handle XML encryption
during parsing. An attacker could possibly use this issue to consume
excessive resources, resulting in a denial of service. (CVE-2026-47302)
Pham Quang Minh discovered that .NET did not properly parse
authentication data. An attacker could possibly use this issue to bypass
authentication and elevate privileges. (CVE-2026-47303)
Levi Broderick discovered that .NET did not properly verify cryptographic
signatures during XML encryption. An attacker could possibly use th
Red Hat
ASP.NET Core: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm
vendor_redhat·2026-07-14·CVSS 8.8
CVE-2026-47300 [HIGH] CWE-303 ASP.NET Core: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm
ASP.NET Core: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm
Incorrect implementation of authentication algorithm in ASP.NET Core allows an authorized attacker to elevate privileges over a network.
A flaw was found in ASP.NET Core. An authorized attacker can exploit an incorrect implementation of the authentication algorithm over a network. This vulnerability allows the attacker to elevate their privileges, potentially gaining unauthorized access to sensitive resources or performing actions beyond their intended permissions.
Package: dotnet10.0 (Red Hat Enterprise Linux 10) - Affected
Package: dotnet8.0 (Red Hat Enterprise Linux 10) - Affected
Package: dotnet9.0 (Red Hat Enterprise Linux 10) - Affected
Package: dotnet10.0 (Red Hat Enterprise Linux 8) - Affe
GHSA
Microsoft Security Advisory CVE-2026-47300 – .NET Elevation of Privilege Vulnerability
ghsa·2026-07-21·CVSS 8.8
CVE-2026-47300 [HIGH] CWE-303 Microsoft Security Advisory CVE-2026-47300 – .NET Elevation of Privilege Vulnerability
Microsoft Security Advisory CVE-2026-47300 – .NET Elevation of Privilege Vulnerability
## Executive summary
Microsoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core Negotiate Authentication (Microsoft.AspNetCore.Authentication.Negotiate). This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.
An elevation of privilege vulnerability exists in the ASP.NET Core Negotiate authentication handler in .NET 8, .NET 9, and .NET 10 due to improper validation.
## Announcement
Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/**TBD**
## CVSS Details
- **Version:** 3.1
- **Severity:** High
- **Score:** 8.8
- **Vector:** `CVSS:3.1/AV:N/AC:L/P
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-47300 dotnet9.0: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm [fedora-all]
bugzilla·2026-07-16·CVSS 8.8
CVE-2026-47300 [HIGH] CVE-2026-47300 dotnet9.0: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm [fedora-all]
CVE-2026-47300 dotnet9.0: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Incorrect implementation of authentication algorithm in ASP.NET Core allows an authorized attacker to elevate privileges over a network.
Bugzilla
CVE-2026-47300 dotnet10.0: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm [fedora-all]
bugzilla·2026-07-16·CVSS 8.8
CVE-2026-47300 [HIGH] CVE-2026-47300 dotnet10.0: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm [fedora-all]
CVE-2026-47300 dotnet10.0: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Incorrect implementation of authentication algorithm in ASP.NET Core allows an authorized attacker to elevate privileges over a network.
Bugzilla
CVE-2026-47300 dotnet8.0: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm [fedora-all]
bugzilla·2026-07-16·CVSS 8.8
CVE-2026-47300 [HIGH] CVE-2026-47300 dotnet8.0: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm [fedora-all]
CVE-2026-47300 dotnet8.0: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Incorrect implementation of authentication algorithm in ASP.NET Core allows an authorized attacker to elevate privileges over a network.
Bugzilla
CVE-2026-47300 ASP.NET Core: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm
bugzilla·2026-07-14·CVSS 8.8
CVE-2026-47300 [HIGH] CVE-2026-47300 ASP.NET Core: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm
CVE-2026-47300 ASP.NET Core: ASP.NET Core: Privilege Escalation via Incorrect Authentication Algorithm
Incorrect implementation of authentication algorithm in ASP.NET Core allows an authorized attacker to elevate privileges over a network.
Rapid7
Patch Tuesday - July 2026
blogs_rapid7·2026-07-14·CVSS 9.6
CVE-2026-58617 [CRITICAL] Patch Tuesday - July 2026
Microsoft is publishing 622 vulnerabilities on July 2026 Patch Tuesday , including a record-breaking 416 Windows vulnerabilities. Microsoft is aware of exploitation in the wild for two of the vulnerabilities published today, both of which are listed on CISA KEV, as well as public disclosure for one other. As usual, browser vulns are not included in the Patch Tuesday count above. Rapid7 noted last month that Microsoft no longer enumerates Chromium CVEs in the Security Update Guide. However, Microsoft has now taken the pursuit of minimalism much further, since today’s Security Update Guide no longer lists out even Microsoft vulnerabilities! Instead, we now receive a summary table of vulnerability counts by product family, as well as a new slimline “Notable CVEs” section. All of this only ser
Sans Isc
Microsoft Patch Tuesday July 2026 - The AI Acopolypse is Here , (Tue, Jul 14th)
blogs_sans_isc·2026-07-14·CVSS 6.1
CVE-2026-56155 [MEDIUM] Microsoft Patch Tuesday July 2026 - The AI Acopolypse is Here , (Tue, Jul 14th)
Microsoft Patch Tuesday July 2026 - The AI Acopolypse is Here
Published: 2026-07-14. Last Updated: 2026-07-14 19:14:58 UTC
by Johannes Ullrich (Version: 1)
0 comment(s)
This patch Tuesday includes a staggering 622 vulnerabilities, not including another 427 vulnerabilities in Chromium, affecting Microsoft's Edge browser. 62 of the vulnerabilities are rated critical. One was disclosed before today, and two have already been exploited.
Given the large number of vulnerabilities, it is difficult to point out "noteworthy" issues.
Already exploited vulnerabilities:
CVE-2026-56155 : Active Directory Federation Services Elevation of Privilege Vulnerability. This is an important (not critical) vulnerablity.
CVE-2026-56164: Microsoft SharePoint Server Elevation of Privilege Vulnerability. Micr
2026-07-14
Published