Vulnerability-Lookup

(CVE-2026-94439)

Vulnerability from cleanstart – Published: 2026-10-13 00:37 – Updated: 2026-10-12 07:59 – Source website

Summary

Details

CVE-2026-94439 affects multiple packages. When an HTTP server handler sends a 2xx response to an HTTP/1 CONNECT request and returns without hijacking the connection, the server improperly continues to read and serve requests from the connection. See references for individual vulnerability details.

Severity

7.5 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

URL

Type

	https://github.com/cleanstart-dev/cleanstart-secu…	ADVISORY
	https://osv.dev/vulnerability/CVE-2026-94439	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-94439	WEB

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "CleanStart",
        "name": "ollama-fips",
        "purl": "pkg:apk/cleanstart/ollama-fips?arch=x86_64"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.34.4-r5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "CleanStart",
        "name": "ollama-fips",
        "purl": "pkg:apk/cleanstart/ollama-fips?arch=aarch64"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.34.4-r5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "CleanStart",
        "name": "vt-cli",
        "purl": "pkg:apk/cleanstart/vt-cli"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.1.1-r2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "CleanStart",
        "name": "vt-cli",
        "purl": "pkg:apk/cleanstart/vt-cli"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.3.1-r2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "credits": [],
  "database_specific": {},
  "details": "CVE-2026-94439 affects multiple packages. When an HTTP server handler sends a 2xx response to an HTTP/1 CONNECT request and returns without hijacking the connection, the server improperly continues to read and serve requests from the connection. See references for individual vulnerability details.",
  "id": "CLEANSTART-2026-QO55945",
  "modified": "2026-10-12T07:59:03Z",
  "published": "2026-10-13T00:37:29.173989Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/cleanstart-dev/cleanstart-security-advisories/tree/main/advisories/2026/CLEANSTART-2026-QO55945.json"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-94439"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-94439"
    }
  ],
  "related": [],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "When an HTTP server handler sends a 2xx response to an HTTP/1 CONNECT request and returns without hijacking the connection, the server improperly continues to read and serve requests from the conne...",
  "upstream": [
    "CVE-2026-94439"
  ]
}

CVE-2026-94439 (GCVE-0-2026-94439)

Vulnerability from cvelistv5 – Published: 2026-10-08 22:53 – Updated: 2026-10-09 16:52

Title

HTTP/1 server connection desynchronization after 2xx CONNECT response in net/http

Summary

When an HTTP server handler sends a 2xx response to an HTTP/1 CONNECT request and returns without hijacking the connection, the server improperly continues to read and serve requests from the connection. Since a 2xx response to an HTTP/1 CONNECT converts the connection into a tunnel, the server should not treat the connection as continuing to contain HTTP. The impact of this misbehavior is mostly limited to potential request smuggling, where an intermediate proxy considers the data on the connection to be tunneled and the server considers it to be HTTP.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-09 16:45 UTC

CWE

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

Assigner

Go CNA under the Google root

CNA scorecard E 42/100 over 75 records in the last 180 days details

References

4 references

URL	Tags
https://go.dev/cl/847311
https://go.dev/issue/81744
https://groups.google.com/g/golang-announce/c/U2f…
https://pkg.go.dev/vuln/GO-2026-6613

Impacted products

1 product

Vendor	Product	Version
Go standard library	net/http	Affected: 0 , < 1.26.9 (semver) Affected: 1.27.0-0 , < 1.27.2 (semver)

Credits

Jakub Ciolek (https://ciolek.dev)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-94439",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-09T16:45:53.919403Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-444",
                "description": "CWE-444 Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-09T16:52:15.154Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "net/http",
          "product": "net/http",
          "programRoutines": [
            {
              "name": "chunkWriter.writeHeader"
            },
            {
              "name": "CanonicalHeaderKey"
            },
            {
              "name": "Client.CloseIdleConnections"
            },
            {
              "name": "Client.Do"
            },
            {
              "name": "Client.Get"
            },
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              "name": "Client.Head"
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              "name": "Client.PostForm"
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              "name": "ClientConn.Close"
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              "name": "Cookie.String"
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              "name": "Cookie.Valid"
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            {
              "name": "CrossOriginProtection.AddInsecureBypassPattern"
            },
            {
              "name": "CrossOriginProtection.AddTrustedOrigin"
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            {
              "name": "CrossOriginProtection.Check"
            },
            {
              "name": "Dir.Open"
            },
            {
              "name": "Error"
            },
            {
              "name": "Get"
            },
            {
              "name": "Handle"
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            {
              "name": "HandleFunc"
            },
            {
              "name": "HandlerFunc.ServeHTTP"
            },
            {
              "name": "Head"
            },
            {
              "name": "Header.Add"
            },
            {
              "name": "Header.Del"
            },
            {
              "name": "Header.Get"
            },
            {
              "name": "Header.Set"
            },
            {
              "name": "Header.Values"
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            {
              "name": "Header.Write"
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            {
              "name": "Header.WriteSubset"
            },
            {
              "name": "ListenAndServe"
            },
            {
              "name": "ListenAndServeTLS"
            },
            {
              "name": "NewRequest"
            },
            {
              "name": "NewRequestWithContext"
            },
            {
              "name": "NotFound"
            },
            {
              "name": "ParseCookie"
            },
            {
              "name": "ParseSetCookie"
            },
            {
              "name": "ParseTime"
            },
            {
              "name": "Post"
            },
            {
              "name": "PostForm"
            },
            {
              "name": "ProxyFromEnvironment"
            },
            {
              "name": "ReadRequest"
            },
            {
              "name": "ReadResponse"
            },
            {
              "name": "Redirect"
            },
            {
              "name": "Request.AddCookie"
            },
            {
              "name": "Request.BasicAuth"
            },
            {
              "name": "Request.Cookie"
            },
            {
              "name": "Request.Cookies"
            },
            {
              "name": "Request.CookiesNamed"
            },
            {
              "name": "Request.FormFile"
            },
            {
              "name": "Request.FormValue"
            },
            {
              "name": "Request.MultipartReader"
            },
            {
              "name": "Request.ParseForm"
            },
            {
              "name": "Request.ParseMultipartForm"
            },
            {
              "name": "Request.PostFormValue"
            },
            {
              "name": "Request.Referer"
            },
            {
              "name": "Request.SetBasicAuth"
            },
            {
              "name": "Request.UserAgent"
            },
            {
              "name": "Request.Write"
            },
            {
              "name": "Request.WriteProxy"
            },
            {
              "name": "Response.Cookies"
            },
            {
              "name": "Response.Location"
            },
            {
              "name": "Response.Write"
            },
            {
              "name": "ResponseController.EnableFullDuplex"
            },
            {
              "name": "ResponseController.Flush"
            },
            {
              "name": "ResponseController.Hijack"
            },
            {
              "name": "ResponseController.SetReadDeadline"
            },
            {
              "name": "ResponseController.SetWriteDeadline"
            },
            {
              "name": "Serve"
            },
            {
              "name": "ServeContent"
            },
            {
              "name": "ServeFile"
            },
            {
              "name": "ServeFileFS"
            },
            {
              "name": "ServeMux.Handle"
            },
            {
              "name": "ServeMux.HandleFunc"
            },
            {
              "name": "ServeMux.ServeHTTP"
            },
            {
              "name": "ServeTLS"
            },
            {
              "name": "Server.Close"
            },
            {
              "name": "Server.ListenAndServe"
            },
            {
              "name": "Server.ListenAndServeTLS"
            },
            {
              "name": "Server.Serve"
            },
            {
              "name": "Server.ServeTLS"
            },
            {
              "name": "Server.SetKeepAlivesEnabled"
            },
            {
              "name": "Server.Shutdown"
            },
            {
              "name": "SetCookie"
            },
            {
              "name": "Transport.CancelRequest"
            },
            {
              "name": "Transport.Clone"
            },
            {
              "name": "Transport.CloseIdleConnections"
            },
            {
              "name": "Transport.NewClientConn"
            },
            {
              "name": "Transport.RoundTrip"
            },
            {
              "name": "body.Close"
            },
            {
              "name": "body.Read"
            },
            {
              "name": "bodyEOFSignal.Close"
            },
            {
              "name": "bodyEOFSignal.Read"
            },
            {
              "name": "bodyLocked.Read"
            },
            {
              "name": "bufioFlushWriter.Write"
            },
            {
              "name": "cancelTimerBody.Close"
            },
            {
              "name": "cancelTimerBody.Read"
            },
            {
              "name": "checkConnErrorWriter.Write"
            },
            {
              "name": "chunkWriter.Write"
            },
            {
              "name": "connReader.Read"
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            {
              "name": "connectMethodKey.String"
            },
            {
              "name": "expectContinueReader.Close"
            },
            {
              "name": "expectContinueReader.Read"
            },
            {
              "name": "extraHeader.Write"
            },
            {
              "name": "fileHandler.ServeHTTP"
            },
            {
              "name": "fileTransport.RoundTrip"
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            {
              "name": "globalOptionsHandler.ServeHTTP"
            },
            {
              "name": "gzipReader.Close"
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              "name": "gzipReader.Read"
            },
            {
              "name": "http1ClientConn.Close"
            },
            {
              "name": "http1ClientConn.RoundTrip"
            },
            {
              "name": "http2ClientConn.RoundTrip"
            },
            {
              "name": "http2Handler.ServeHTTP"
            },
            {
              "name": "http2ResponseWriter.Flush"
            },
            {
              "name": "http2ResponseWriter.FlushError"
            },
            {
              "name": "http2ResponseWriter.Push"
            },
            {
              "name": "http2RoundTripper.RoundTrip"
            },
            {
              "name": "http3ServerHandler.ServeHTTP"
            },
            {
              "name": "initALPNRequest.ServeHTTP"
            },
            {
              "name": "loggingConn.Close"
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            {
              "name": "loggingConn.Read"
            },
            {
              "name": "loggingConn.Write"
            },
            {
              "name": "maxBytesReader.Close"
            },
            {
              "name": "maxBytesReader.Read"
            },
            {
              "name": "onceCloseListener.Close"
            },
            {
              "name": "persistConn.Read"
            },
            {
              "name": "persistConnWriter.ReadFrom"
            },
            {
              "name": "persistConnWriter.Write"
            },
            {
              "name": "populateResponse.Write"
            },
            {
              "name": "populateResponse.WriteHeader"
            },
            {
              "name": "readTrackingBody.Close"
            },
            {
              "name": "readTrackingBody.Read"
            },
            {
              "name": "readWriteCloserBody.CloseWrite"
            },
            {
              "name": "readWriteCloserBody.Read"
            },
            {
              "name": "redirectHandler.ServeHTTP"
            },
            {
              "name": "response.Flush"
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            {
              "name": "response.FlushError"
            },
            {
              "name": "response.Hijack"
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            {
              "name": "response.ReadFrom"
            },
            {
              "name": "response.Write"
            },
            {
              "name": "response.WriteHeader"
            },
            {
              "name": "response.WriteString"
            },
            {
              "name": "serverHandler.ServeHTTP"
            },
            {
              "name": "socksDialer.DialWithConn"
            },
            {
              "name": "socksUsernamePassword.Authenticate"
            },
            {
              "name": "stringWriter.WriteString"
            },
            {
              "name": "timeoutHandler.ServeHTTP"
            },
            {
              "name": "timeoutWriter.Write"
            },
            {
              "name": "timeoutWriter.WriteHeader"
            },
            {
              "name": "transportReadFromServerError.Error"
            },
            {
              "name": "unencryptedHTTP2Request.ServeHTTP"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
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              "version": "0",
              "versionType": "semver"
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        }
      ],
      "credits": [
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          "value": "Jakub Ciolek (https://ciolek.dev)"
        }
      ],
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          "value": "When an HTTP server handler sends a 2xx response to an HTTP/1 CONNECT request and returns without hijacking the connection, the server improperly continues to read and serve requests from the connection. Since a 2xx response to an HTTP/1 CONNECT converts the connection into a tunnel, the server should not treat the connection as continuing to contain HTTP. The impact of this misbehavior is mostly limited to potential request smuggling, where an intermediate proxy considers the data on the connection to be tunneled and the server considers it to be HTTP."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-444: Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)",
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      ],
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        "dateUpdated": "2026-10-08T22:53:59.976Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
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        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-6613"
        }
      ],
      "title": "HTTP/1 server connection desynchronization after 2xx CONNECT response in net/http"
    }
  },
  "cveMetadata": {
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    "cveId": "CVE-2026-94439",
    "datePublished": "2026-10-08T22:53:59.976Z",
    "dateReserved": "2026-09-21T16:43:04.757Z",
    "dateUpdated": "2026-10-09T16:52:15.154Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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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.

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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