{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-72916",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-08-10T17:57:26.143Z",
        "datePublished": "2026-08-10T21:19:02.908Z",
        "dateUpdated": "2026-08-13T15:13:23.011Z"
    },
    "containers": {
        "cna": {
            "title": "Mastodon: SSRF Protection Bypass via IPv4-compatible IPv6 Addresses",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-918",
                            "lang": "en",
                            "description": "CWE-918: Server-Side Request Forgery (SSRF)",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-1286",
                            "lang": "en",
                            "description": "CWE-1286: Improper Validation of Syntactic Correctness of Input",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "HIGH",
                        "attackRequirements": "PRESENT",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "NONE",
                        "vulnIntegrityImpact": "NONE",
                        "vulnAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "LOW",
                        "subIntegrityImpact": "LOW",
                        "subAvailabilityImpact": "LOW",
                        "baseScore": 6.3,
                        "baseSeverity": "MEDIUM",
                        "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:L",
                        "version": "4.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/mastodon/mastodon/security/advisories/GHSA-vwhj-3g83-v276",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/mastodon/mastodon/security/advisories/GHSA-vwhj-3g83-v276"
                },
                {
                    "name": "https://github.com/mastodon/mastodon/commit/18c61f286f1f5718a8f517940ba384866ffa3892",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mastodon/mastodon/commit/18c61f286f1f5718a8f517940ba384866ffa3892"
                },
                {
                    "name": "https://github.com/mastodon/mastodon/commit/467c933459c7d0e5513475b9e4888afaedfb1074",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mastodon/mastodon/commit/467c933459c7d0e5513475b9e4888afaedfb1074"
                },
                {
                    "name": "https://github.com/mastodon/mastodon/commit/930aa9fee26bf9eaefe27826fa1061288d83373b",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mastodon/mastodon/commit/930aa9fee26bf9eaefe27826fa1061288d83373b"
                },
                {
                    "name": "https://github.com/mastodon/mastodon/commit/da47a1bd3cd07935d7ca55a1f4f1a76f7f167e0d",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mastodon/mastodon/commit/da47a1bd3cd07935d7ca55a1f4f1a76f7f167e0d"
                },
                {
                    "name": "https://github.com/mastodon/mastodon/releases/tag/v4.4.21",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mastodon/mastodon/releases/tag/v4.4.21"
                },
                {
                    "name": "https://github.com/mastodon/mastodon/releases/tag/v4.5.14",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mastodon/mastodon/releases/tag/v4.5.14"
                },
                {
                    "name": "https://github.com/mastodon/mastodon/releases/tag/v4.6.4",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mastodon/mastodon/releases/tag/v4.6.4"
                },
                {
                    "name": "https://github.com/mastodon/mastodon/releases/tag/v4.7.0-beta.1",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mastodon/mastodon/releases/tag/v4.7.0-beta.1"
                }
            ],
            "affected": [
                {
                    "vendor": "mastodon",
                    "product": "mastodon",
                    "versions": [
                        {
                            "version": "< 4.4.21",
                            "status": "affected"
                        },
                        {
                            "version": ">= 4.5.0-beta.1, < 4.5.14",
                            "status": "affected"
                        },
                        {
                            "version": ">= 4.6.0-beta.1, < 4.6.4",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-08-10T21:19:02.908Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.4.21, 4.5.14, 4.6.4, and 4.7.0-beta.1, PrivateAddressCheck.private_address? in app/lib/private_address_check.rb normalized IPv4-mapped IPv6 addresses but did not recognize IPv4-compatible IPv6 addresses with IPAddr#ipv4_compat?. An attacker could supply an address in the omitted range to bypass the ALLOWED_PRIVATE_ADDRESSES protection and make Mastodon send HTTP requests to loopback interfaces, potentially accessing private resources and services. Exploitation requires a system that supports the obsolete IPv4-compatible IPv6 mechanism. This issue is fixed in versions 4.4.21, 4.5.14, 4.6.4, and 4.7.0-beta.1."
                }
            ],
            "source": {
                "advisory": "GHSA-vwhj-3g83-v276",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-08-13T15:13:13.639949Z",
                                "id": "CVE-2026-72916",
                                "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": "2026-08-13T15:13:23.011Z"
                }
            }
        ]
    }
}