Vulnerability-Lookup

FKIE_CVE-2026-39830

Vulnerability from fkie_nvd - Published: 2026-05-22 04:16 - Updated: 2026-05-22 04:16

Severity

Summary

A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded.

References

	URL	Tags
	security@golang.org	https://go.dev/cl/781640
	security@golang.org	https://go.dev/cl/781664
	security@golang.org	https://go.dev/issue/79564
	security@golang.org	https://groups.google.com/g/golang-announce/c/a082jnz-LvI
	security@golang.org	https://pkg.go.dev/vuln/GO-2026-5017

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection\u0027s read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded."
    }
  ],
  "id": "CVE-2026-39830",
  "lastModified": "2026-05-22T04:16:22.440",
  "metrics": {},
  "published": "2026-05-22T04:16:22.440",
  "references": [
    {
      "source": "security@golang.org",
      "url": "https://go.dev/cl/781640"
    },
    {
      "source": "security@golang.org",
      "url": "https://go.dev/cl/781664"
    },
    {
      "source": "security@golang.org",
      "url": "https://go.dev/issue/79564"
    },
    {
      "source": "security@golang.org",
      "url": "https://groups.google.com/g/golang-announce/c/a082jnz-LvI"
    },
    {
      "source": "security@golang.org",
      "url": "https://pkg.go.dev/vuln/GO-2026-5017"
    }
  ],
  "sourceIdentifier": "security@golang.org",
  "vulnStatus": "Received"
}

CVE-2026-39830 (GCVE-0-2026-39830)

Vulnerability from cvelistv5 – Published: 2026-05-22 02:31 – Updated: 2026-05-22 18:54

Title

Invoking client can cause server deadlock on unexpected responses in golang.org/x/crypto/ssh

Summary

Severity

9.1 (Critical)


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

CWE

CWE-833 - Deadlock

Assigner

References

5 references

URL	Tags
https://go.dev/issue/79564
https://groups.google.com/g/golang-announce/c/a08…
https://go.dev/cl/781640
https://go.dev/cl/781664
https://pkg.go.dev/vuln/GO-2026-5017

Impacted products

1 product

Vendor	Product	Version
golang.org/x/crypto	golang.org/x/crypto/ssh	Affected: 0 , < 0.52.0 (semver)

Credits

NCC Group Cryptography Services, sponsored by Teleport

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 9.1,
              "baseSeverity": "CRITICAL",
              "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:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-39830",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-22T18:54:26.306252Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-22T18:54:54.686Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "golang.org/x/crypto/ssh",
          "product": "golang.org/x/crypto/ssh",
          "programRoutines": [
            {
              "name": "mux.SendRequest"
            },
            {
              "name": "mux.handleGlobalPacket"
            },
            {
              "name": "channel.handlePacket"
            },
            {
              "name": "channel.SendRequest"
            },
            {
              "name": "Client.Listen"
            },
            {
              "name": "Client.ListenTCP"
            },
            {
              "name": "Client.ListenUnix"
            },
            {
              "name": "Dial"
            },
            {
              "name": "NewClientConn"
            },
            {
              "name": "NewServerConn"
            },
            {
              "name": "Session.CombinedOutput"
            },
            {
              "name": "Session.Output"
            },
            {
              "name": "Session.RequestPty"
            },
            {
              "name": "Session.RequestSubsystem"
            },
            {
              "name": "Session.Run"
            },
            {
              "name": "Session.SendRequest"
            },
            {
              "name": "Session.Setenv"
            },
            {
              "name": "Session.Shell"
            },
            {
              "name": "Session.Signal"
            },
            {
              "name": "Session.Start"
            },
            {
              "name": "Session.WindowChange"
            },
            {
              "name": "tcpListener.Close"
            },
            {
              "name": "unixListener.Close"
            }
          ],
          "vendor": "golang.org/x/crypto",
          "versions": [
            {
              "lessThan": "0.52.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "NCC Group Cryptography Services, sponsored by Teleport"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection\u0027s read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-833: Deadlock",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-22T02:31:27.208Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/issue/79564"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/a082jnz-LvI"
        },
        {
          "url": "https://go.dev/cl/781640"
        },
        {
          "url": "https://go.dev/cl/781664"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-5017"
        }
      ],
      "title": "Invoking  client can cause server deadlock on unexpected responses in golang.org/x/crypto/ssh"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-39830",
    "datePublished": "2026-05-22T02:31:27.208Z",
    "dateReserved": "2026-04-07T18:13:03.528Z",
    "dateUpdated": "2026-05-22T18:54:54.686Z",
    "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.

Detection rules are retrieved from Rulezet.

Action not permitted

FKIE_CVE-2026-39830

CVE-2026-39830 (GCVE-0-2026-39830)

Tags

Sightings

Nomenclature