Vulnerability-Lookup

FKIE_CVE-2026-39832

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

Severity

Summary

When adding a key to a remote agent constraint extensions such as restrict-destination-v00@openssh.com were not serialized in the request. Destination restrictions were silently stripped when forwarding keys, allowing unrestricted use of the key on the remote host. The client now serializes all constraint extensions. Additionally, the in-memory keyring returned by NewKeyring() now rejects keys with unsupported constraint extensions instead of silently ignoring them.

References

	URL	Tags
	security@golang.org	https://go.dev/cl/778642
	security@golang.org	https://go.dev/issue/79435
	security@golang.org	https://groups.google.com/g/golang-announce/c/a082jnz-LvI
	security@golang.org	https://pkg.go.dev/vuln/GO-2026-5006

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "When adding a key to a remote agent constraint extensions such as restrict-destination-v00@openssh.com were not serialized in the request. Destination restrictions were silently stripped when forwarding keys, allowing unrestricted use of the key on the remote host. The client now serializes all constraint extensions. Additionally, the in-memory keyring returned by NewKeyring() now rejects keys with unsupported constraint extensions instead of silently ignoring them."
    }
  ],
  "id": "CVE-2026-39832",
  "lastModified": "2026-05-22T04:16:22.663",
  "metrics": {},
  "published": "2026-05-22T04:16:22.663",
  "references": [
    {
      "source": "security@golang.org",
      "url": "https://go.dev/cl/778642"
    },
    {
      "source": "security@golang.org",
      "url": "https://go.dev/issue/79435"
    },
    {
      "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-2026-5006"
    }
  ],
  "sourceIdentifier": "security@golang.org",
  "vulnStatus": "Received"
}

CVE-2026-39832 (GCVE-0-2026-39832)

Vulnerability from cvelistv5 – Published: 2026-05-22 02:31 – Updated: 2026-05-22 19:03

Title

Invoking agent constraints dropped when forwarding keys in golang.org/x/crypto/ssh/agent

Summary

Severity

9.1 (Critical)


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

CWE

CWE-281 - Improper Preservation of Permissions

Assigner

References

4 references

URL	Tags
https://go.dev/issue/79435
https://go.dev/cl/778642
https://groups.google.com/g/golang-announce/c/a08…
https://pkg.go.dev/vuln/GO-2026-5006

Impacted products

1 product

Vendor	Product	Version
golang.org/x/crypto	golang.org/x/crypto/ssh/agent	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": "NONE",
              "baseScore": 9.1,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-39832",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-22T18:59:53.174504Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-22T19:03:06.882Z",
          "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/agent",
          "product": "golang.org/x/crypto/ssh/agent",
          "programRoutines": [
            {
              "name": "client.Add"
            },
            {
              "name": "keyring.Add"
            }
          ],
          "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": "When adding a key to a remote agent constraint extensions such as restrict-destination-v00@openssh.com were not serialized in the request. Destination restrictions were silently stripped when forwarding keys, allowing unrestricted use of the key on the remote host. The client now serializes all constraint extensions. Additionally, the in-memory keyring returned by NewKeyring() now rejects keys with unsupported constraint extensions instead of silently ignoring them."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-281: Improper Preservation of Permissions",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-22T02:31:26.660Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/issue/79435"
        },
        {
          "url": "https://go.dev/cl/778642"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/a082jnz-LvI"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-5006"
        }
      ],
      "title": "Invoking  agent constraints dropped when forwarding keys in golang.org/x/crypto/ssh/agent"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-39832",
    "datePublished": "2026-05-22T02:31:26.660Z",
    "dateReserved": "2026-04-07T18:13:03.529Z",
    "dateUpdated": "2026-05-22T19:03:06.882Z",
    "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-2026-39832

CVE-2026-39832 (GCVE-0-2026-39832)

Tags

Sightings

Nomenclature