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CVE-2026-62899medium5.9

.NET Security Feature Bypass Vulnerability

Impact

The .NET 8.0, 9.0, and 10.0 runtimes, and Microsoft Visual Studio 2022 and 2026, are affected by a security feature bypass vulnerability due to inconsistent interpretation of HTTP requests. An attacker with network access can exploit this weakness. The impact is a security feature bypass.

Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.

Affected packages

This source has no supported package-version data for matching. You can read the advisory here, but this record alone cannot power a dependency check.

Affected products

Vendor version evidence. Product records are separate from automatic dependency matching.

Microsoft · microsoft

.NET 10.0 runtime

1 range
microsoft version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

10.0.0 → before 10.0.11

custom versions

unaffected

unknown

Other versions: unknown

Microsoft · microsoft

.NET 8.0 runtime

1 range
microsoft version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

8.0.0 → before 8.0.30

custom versions

unaffected

unknown

Other versions: unknown

Microsoft · microsoft

.NET 9.0 runtime

1 range
microsoft version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

9.0.0 → before 9.0.19

custom versions

unaffected

unknown

Other versions: unknown

Microsoft · microsoft

Microsoft Visual Studio 2022 version 17.14

1 range
microsoft version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

17.14.0 → before 17.14.38

custom versions

unaffected

unknown

Other versions: unknown

Microsoft · microsoft

Microsoft Visual Studio 2026 version 18.8

1 range
microsoft version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

18.0 → before 18.8.3

custom versions

unaffected

unknown

Other versions: unknown

Original source description

Inconsistent interpretation of http requests ('http request/response smuggling') in .NET allows an unauthorized attacker to bypass a security feature over a network.

Inside the record

Evidence available

Package identity · not supplied
Version evidence
Remediation guidance · not supplied
Weakness classification
Additional publishers

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-62899

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Underlying weaknesses

The source’s classification of what caused the vulnerability.

CWE-444 ↗

CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

microsoft

Related →

Environment requirements

These conditions apply together as specified by the publisher. A matching product name alone does not establish exposure.

microsoft · platform conditions

Any condition may hold

Vulnerable product

cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*

From (inclusive): 10.0.0

Before: 10.0.11

Vulnerable product

cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*

From (inclusive): 8.0.0

Before: 8.0.30

Vulnerable product

cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*

From (inclusive): 9.0.0

Before: 9.0.19

Vulnerable product

cpe:2.3:a:microsoft:visual_studio_2022:*:*:*:*:*:*:*:*

From (inclusive): 17.14.0

Before: 17.14.38

Vulnerable product

cpe:2.3:a:microsoft:visual_studio_2026:*:*:*:*:*:*:*:*

From (inclusive): 18.0

Before: 18.8.3

Original applicability statements
[
  {
    "nodes": [
      {
        "operator": "OR",
        "negate": false,
        "cpeMatch": [
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "10.0.0",
            "versionEndExcluding": "10.0.11"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "8.0.0",
            "versionEndExcluding": "8.0.30"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "9.0.0",
            "versionEndExcluding": "9.0.19"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:visual_studio_2022:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "17.14.0",
            "versionEndExcluding": "17.14.38"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:a:microsoft:visual_studio_2026:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "18.0",
            "versionEndExcluding": "18.8.3"
          }
        ]
      }
    ]
  }
]
Contributing organizations · 2
microsoft

Assigning organization

2026-10-30
CISA-ADP

Additional data publisher

2026-08-12

What changed

Follow changes
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Large field values are marked as truncated previews. Original source snapshots remain retained.

References

1 sources
msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62899
vendor-advisorymicrosoft