CVE-2021-26423 (GCVE-0-2021-26423)
Vulnerability from cvelistv5 – Published: 2021-08-12 18:11 – Updated: 2026-08-10 15:09
VLAI
EPSS
VEX
Title
.NET Core and Visual Studio Denial of Service Vulnerability
Summary
.NET Core and Visual Studio Denial of Service Vulnerability
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-06-04 13:28 UTC
CWE
- Denial of Service
- CWE-noinfo Not enough information
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://msrc.microsoft.com/update-guide/vulnerabi… | vendor-advisorypatch |
| https://portal.msrc.microsoft.com/en-US/security-… | x_refsource_MISCx_transferred |
Impacted products
11 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Microsoft | .NET 5.0 |
Affected:
5.0.0 , < 5.0.9
(custom)
|
guessed | |
| Microsoft | .NET Core 2.1 |
Affected:
2.1 , < 2.1.30
(custom)
|
guessed | |
| Microsoft | .NET Core 3.1 |
Affected:
3.1 , < 3.1.18
(custom)
|
guessed | |
| Microsoft | Microsoft Visual Studio 2017 version 15.9 (includes 15.0 - 15.8) |
Affected:
15.9.0 , < 15.9.38
(custom)
|
guessed | |
| Microsoft | Microsoft Visual Studio 2019 version 16.10 (includes 16.0 - 16.9) |
Affected:
16.10.0 , < 16.10.5
(custom)
|
guessed | |
| Microsoft | Microsoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3) |
Affected:
16.0 , < 16.4.25
(custom)
|
guessed | |
| Microsoft | Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6) |
Affected:
16.0.0 , < 16.7.18
(custom)
|
guessed | |
| Microsoft | Microsoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8) |
Affected:
15.0.0 , < 16.9.10
(custom)
|
guessed | |
| Microsoft | PowerShell Core 7.0 |
Affected:
7.0.0 , < 7.0.7
(custom)
|
guessed | |
| Microsoft | PowerShell Core 7.1 |
Affected:
7.1.0 , < 7.1.4
(custom)
|
guessed | |
| Microsoft | Visual Studio 2019 for Mac version 8.10 |
Affected:
8.1.0 , < 8.10.7
(custom)
|
guessed |
Date Public
2021-08-10 14:00
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}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
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.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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