Affects ASP.NET Core, a widely used web framework; authentication flaw enabling privilege escalation can impact many enterprise web apps and services.
CVE-2026-47300
Authentication bug in ASP.NET Core allows remote privilege escalation.
Is CVE-2026-47300 being exploited?
Not confirmed. CVE-2026-47300 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.53% probability of exploitation in the next 30 days.
How severe is CVE-2026-47300?
CVE-2026-47300 is rated High. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-47300?
Yes. A fix has been recorded for CVE-2026-47300. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-47300 affect?
CVE-2026-47300 affects ASP.NET Core authentication component, Applications using ASP.NET Core Identity/auth middleware. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-47300?
Apply vendor patch when available; restrict network access to auth endpoints and enforce least privilege.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated attacker can elevate privileges to admin remotely, alter data, invoke privileged operations, and compromise applications.
Immediate action required
- affected>= 17.12.0 and < 17.12.22
- affected>= 17.14.0 and < 17.14.36
- affected>= 18.0 and < 18.7.4
- affected>= 10.0.0 and < 10.0.10
- affected>= 8.0.0 and < 8.0.29
- affected>= 9.0.0 and < 9.0.18
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.