Cyber Resilience

CVE-2026-47300

Auth Bypass in Microsoft .Net 8.0.0 – 8.0.29

Published
14 July 2026
Modified
22 July 2026
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0053 42th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-47300 is a high-severity Incorrect Implementation of Authentication Algorithm (CWE-303) vulnerability in Microsoft .Net. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 42th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and IA-2 (Identification and Authentication (Organizational Users)) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Incorrect implementation of authentication algorithm in ASP.NET Core allows an authorized attacker to elevate privileges over a network.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

CWE-303 auth implementation flaw in ASP.NET Core enables network-based privilege escalation from authorized access, directly mapping to exploitation for priv esc and public-facing app exploitation.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2024-38229Same product: Apple Macos
CVE-2024-43485Same product: Apple Macos
CVE-2024-43498Same product: Apple Macos
CVE-2024-43499Same product: Apple Macos
CVE-2025-8881Same product: Apple Macos
CVE-2026-50360Same vendor: Microsoft
CVE-2026-41103Same vendor: Microsoft
CVE-2020-37094Shared CWE-303
CVE-2025-21311Same vendor: Microsoft
CVE-2024-0129Same product: Apple Macos

Affected Assets

microsoft
.net
8.0.0 — 8.0.29 · 9.0.0 — 9.0.18 · 10.0.0 — 10.0.6
microsoft
visual studio 2022
17.12.0 — 17.12.22 · 17.14.0 — 17.14.36
microsoft
visual studio 2026
18.7.0 — 18.7.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • IA-2 Identification and Authentication (Organizational Users)
  • AC-6 Least Privilege
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces access decisions derived from authentication results, blocking the privilege escalation that stems from the flawed authentication algorithm.

prevent

Requires reliable identification and authentication of users before granting access, directly addressing the incorrect authentication algorithm implementation.

prevent

Limits privileges to the minimum required, reducing the impact of any successful elevation achieved through the authentication flaw.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require correct implementation of authentication algorithms.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

degrades

Secure authentication control directly requires correct implementation of authentication algorithms.

detects

Security testing can detect flawed authentication implementations but does not prevent them by itself.

degrades

Cryptography control addresses proper use of authentication algorithms but is broader than authentication alone.

prevents

Secure development lifecycle includes verification steps that can catch incorrect authentication implementations.

prevents

Application security requirements can specify correct authentication algorithm use but do not guarantee correct implementation.

prevents

Secure coding practices reduce the likelihood of incorrect authentication algorithm implementation.

References