{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-77164",
        "assignerOrgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1",
        "state": "PUBLISHED",
        "assignerShortName": "hackerone",
        "dateReserved": "2026-08-20T15:00:00.606Z",
        "datePublished": "2026-09-18T01:26:04.650Z",
        "dateUpdated": "2026-09-18T19:41:07.400Z"
    },
    "containers": {
        "cna": {
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Circles' remote-instance signature verification fetches the attacker-supplied keyId URL before trust in the remote instance is established, and explicitly allows local/private addresses for this request, bypassing Nextcloud's core SSRF protections. The public, unauthenticated endpoints POST /apps/circles/event/ and POST /apps/circles/incoming/ reach this code path, allowing any unauthenticated user to force the server to issue a GET request to an internal address.\n\nThe response body of the internal request is never returned to the requester, so this is blind SSRF: an attacker can determine whether an internal service is reachable, but cannot read its response contents through this endpoint alone."
                }
            ],
            "affected": [
                {
                    "defaultStatus": "unaffected",
                    "vendor": "Nextcloud",
                    "product": "Server",
                    "versions": [
                        {
                            "version": "31.0.0",
                            "status": "affected",
                            "lessThanOrEqual": "32.0.0",
                            "versionType": "semver"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://hackerone.com/reports/3303283"
                }
            ],
            "metrics": [
                {
                    "cvssV3_0": {
                        "version": "3.0",
                        "vectorString": "CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
                        "baseScore": 6.2,
                        "baseSeverity": "MEDIUM"
                    }
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "type": "CWE",
                            "lang": "en",
                            "cweId": "CWE-918",
                            "description": "CWE-918 Server-Side Request Forgery (SSRF)"
                        }
                    ]
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "value": "Balvant Chavda (0x0doteth)",
                    "type": "finder"
                }
            ],
            "providerMetadata": {
                "orgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1",
                "shortName": "hackerone",
                "dateUpdated": "2026-09-18T01:26:04.650Z"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-09-18T19:40:57.953385Z",
                                "id": "CVE-2026-77164",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-09-18T19:41:07.400Z"
                }
            }
        ]
    }
}