CVE-2026-39833 (GCVE-0-2026-39833)

Vulnerability from cvelistv5 – Published: 2026-05-22 02:31 – Updated: 2026-08-11 21:28
VLAI
Title
Invoking key constraints not enforced in golang.org/x/crypto/ssh/agent
Summary
The in-memory keyring returned by NewKeyring() silently accepted keys with the ConfirmBeforeUse constraint but never enforced it. The key would sign without any confirmation prompt, with no indication to the caller that the constraint was not in effect. NewKeyring() now returns an error when unsupported constraints are requested.
Severity
9.1 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
SSVC
Exploitation: none Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-22 18:57 UTC
CWE
  • CWE-358 - Improperly Implemented Security Check for Standard
Assigner
References
Impacted products
Vendor Product Version CPE status
golang.org/x/crypto golang.org/x/crypto/ssh/agent Affected: 0 , < 0.52.0 (semver)
guessed Create a notification for this product.
Credits
NCC Group Cryptography Services, sponsored by Teleport
Show details on NVD website
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-2026-39833",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-22T18:57:41.103317Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-22T18:58:08.489Z",
          "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": "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": "The in-memory keyring returned by NewKeyring() silently accepted keys with the ConfirmBeforeUse constraint but never enforced it. The key would sign without any confirmation prompt, with no indication to the caller that the constraint was not in effect. NewKeyring() now returns an error when unsupported constraints are requested."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-358: Improperly Implemented Security Check for Standard",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-11T21:28:47.545Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/issue/79436"
        },
        {
          "url": "https://go.dev/cl/778642"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/a082jnz-LvI"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-5005"
        }
      ],
      "title": "Invoking  key constraints not enforced in golang.org/x/crypto/ssh/agent"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-39833",
    "datePublished": "2026-05-22T02:31:26.294Z",
    "dateReserved": "2026-04-07T18:13:03.529Z",
    "dateUpdated": "2026-08-11T21:28:47.545Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-39833",
      "date": "2026-10-05",
      "epss": "0.00487",
      "percentile": "0.39776"
    },
    "microsoft_vex": {
      "current_release_date": "2026-06-11T01:42:10.000Z",
      "cve": "CVE-2026-39833",
      "id": "msrc_CVE-2026-39833",
      "initial_release_date": "2026-05-02T00:00:00.000Z",
      "product_status:fixed": "4",
      "product_status:known_affected": "8",
      "product_status:known_not_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "Invoking  key constraints not enforced in golang.org/x/crypto/ssh/agent",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-39833.json",
      "version": "5"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "collectionURL": "https://pkg.go.dev",
                "defaultStatus": "unaffected",
                "packageName": "golang.org/x/crypto/ssh/agent",
                "product": "golang.org/x/crypto/ssh/agent",
                "programRoutines": [
                  {
                    "name": "keyring.Add"
                  }
                ],
                "vendor": "golang.org/x/crypto",
                "versions": [
                  {
                    "lessThan": "0.52.0",
                    "status": "affected",
                    "version": "0",
                    "versionType": "semver"
                  }
                ]
              }
            ],
            "source": "security@golang.org"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:golang:crypto:*:*:*:*:*:go:*:*",
                    "matchCriteriaId": "D540395B-31B8-4B07-8F79-F5C631BBD5C8",
                    "versionEndExcluding": "0.52.0",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "The in-memory keyring returned by NewKeyring() silently accepted keys with the ConfirmBeforeUse constraint but never enforced it. The key would sign without any confirmation prompt, with no indication to the caller that the constraint was not in effect. NewKeyring() now returns an error when unsupported constraints are requested."
          },
          {
            "lang": "es",
            "value": "El llavero en memoria devuelto por NewKeyring() acept\u00f3 silenciosamente claves con la restricci\u00f3n ConfirmBeforeUse pero nunca la aplic\u00f3. La clave firmar\u00eda sin ninguna solicitud de confirmaci\u00f3n, sin ninguna indicaci\u00f3n al llamador de que la restricci\u00f3n no estaba en vigor. NewKeyring() ahora devuelve un error cuando se solicitan restricciones no compatibles."
          }
        ],
        "id": "CVE-2026-39833",
        "lastModified": "2026-08-11T22:17:25.250",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "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"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 5.2,
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-39833",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "yes"
                  },
                  {
                    "technicalImpact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-22T18:57:41.103317Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-05-22T04:16:22.773",
        "references": [
          {
            "source": "security@golang.org",
            "url": "https://go.dev/cl/778642"
          },
          {
            "source": "security@golang.org",
            "tags": [
              "Issue Tracking"
            ],
            "url": "https://go.dev/issue/79436"
          },
          {
            "source": "security@golang.org",
            "tags": [
              "Mailing List"
            ],
            "url": "https://groups.google.com/g/golang-announce/c/a082jnz-LvI"
          },
          {
            "source": "security@golang.org",
            "tags": [
              "Vendor Advisory"
            ],
            "url": "https://pkg.go.dev/vuln/GO-2026-5005"
          }
        ],
        "sourceIdentifier": "security@golang.org",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-862"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-09-10T17:24:47+00:00",
      "cve": "CVE-2026-39833",
      "id": "CVE-2026-39833",
      "initial_release_date": "2026-05-22T02:31:26.294000+00:00",
      "product_status:fixed": "203",
      "product_status:known_affected": "905",
      "product_status:known_not_affected": "448",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "golang.org/x/crypto/ssh/agent: golang.org/x/crypto/ssh/agent: Security bypass due to unenforced key confirmation",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39833.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-10-06T00:01:21Z",
      "cve": "CVE-2026-39833",
      "id": "CVE-2026-39833",
      "initial_release_date": "2026-05-23T01:29:05Z",
      "product_status:known_affected": "327",
      "product_status:known_not_affected": "355",
      "product_status:recommended": "406",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-39833",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-39833.json",
      "version": "49"
    },
    "vulnrichment": {
      "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-2026-39833",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "total"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-05-22T18:57:41.103317Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-05-22T18:58:04.074Z",
              "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": "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": "The in-memory keyring returned by NewKeyring() silently accepted keys with the ConfirmBeforeUse constraint but never enforced it. The key would sign without any confirmation prompt, with no indication to the caller that the constraint was not in effect. NewKeyring() now returns an error when unsupported constraints are requested."
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "description": "CWE-358: Improperly Implemented Security Check for Standard",
                  "lang": "en"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-08-11T21:28:47.545Z",
            "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
            "shortName": "Go"
          },
          "references": [
            {
              "url": "https://go.dev/issue/79436"
            },
            {
              "url": "https://go.dev/cl/778642"
            },
            {
              "url": "https://groups.google.com/g/golang-announce/c/a082jnz-LvI"
            },
            {
              "url": "https://pkg.go.dev/vuln/GO-2026-5005"
            }
          ],
          "title": "Invoking  key constraints not enforced in golang.org/x/crypto/ssh/agent"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "assignerShortName": "Go",
        "cveId": "CVE-2026-39833",
        "datePublished": "2026-05-22T02:31:26.294Z",
        "dateReserved": "2026-04-07T18:13:03.529Z",
        "dateUpdated": "2026-08-11T21:28:47.545Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.



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.