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CVE-2026-21218 (GCVE-0-2026-21218)

Vulnerability from cvelistv5 – Published: 2026-02-10 17:51 – Updated: 2026-08-19 16:25
VLAI
Title
.NET Spoofing Vulnerability
Summary
Improper handling of missing special element in .NET allows an unauthorized attacker to perform spoofing over a network.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-02-11 15:29 UTC
CWE
  • CWE-166 - Improper Handling of Missing Special Element
Assigner
References
Impacted products
Vendor Product Version CPE status
Microsoft .NET 10.0 Affected: 10.0.0 , < 10.0.3 (custom)
guessed Create a notification for this product.
Microsoft .NET 8.0 Affected: 8.0.0 , < 8.0.24 (custom)
guessed Create a notification for this product.
Microsoft .NET 9.0 Affected: 9.0.0 , < 9.0.13 (custom)
guessed Create a notification for this product.
Date Public
2026-02-10 16:00
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.