{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-46482",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-05-14T18:06:06.810Z",
        "datePublished": "2026-08-18T15:44:59.644Z",
        "dateUpdated": "2026-08-18T17:46:31.511Z"
    },
    "containers": {
        "cna": {
            "title": "MyBB: Security Question insufficient validation",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-636",
                            "lang": "en",
                            "description": "CWE-636: Not Failing Securely ('Failing Open')",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 5.3,
                        "baseSeverity": "MEDIUM",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "LOW",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/mybb/mybb/security/advisories/GHSA-v2h7-4jp7-j6hh",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/mybb/mybb/security/advisories/GHSA-v2h7-4jp7-j6hh"
                },
                {
                    "name": "https://github.com/mybb/mybb/commit/bd2a3447939d3084a5926dd66ece04649e0e0d60",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mybb/mybb/commit/bd2a3447939d3084a5926dd66ece04649e0e0d60"
                },
                {
                    "name": "https://github.com/mybb/mybb/releases/tag/mybb_1840",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mybb/mybb/releases/tag/mybb_1840"
                },
                {
                    "name": "https://mybb.com/versions/1.8.40",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://mybb.com/versions/1.8.40"
                }
            ],
            "affected": [
                {
                    "vendor": "mybb",
                    "product": "mybb",
                    "versions": [
                        {
                            "version": "< 1.8.40",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-08-18T15:44:59.644Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "### Impact\nThe registration component does not validate the text-based _Security Question_ CAPTCHA correctly, allowing attackers to bypass the challenge via a specially crafted value.\n\n\n[CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N](https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)\n\n### Details\nThe public _Registration_ workflow ([`member.php?action=do_register`](https://github.com/mybb/mybb/blob/mybb_1839/member.php#L262-L307)) accepts a hidden field `question_id` — expected to match the question session identifier (`mybb_questionsessions.sid`) — and validates the challenge answer without a fail-closed fallback for invalid identifiers. If the value is blank, forged, or expired, the request continues without a question-related error.\n\n### Patches\nMyBB 1.8.(...) resolves this issue with the following changes:\n\n- Commit: https://github.com/mybb/mybb/commit/\n  - `.patch`: https://github.com/mybb/mybb/commit/.patch\n\n### References\n- Release Notes: https://mybb.com/versions/1.8.(...)/\n\n### For more information\nGo to [mybb.com/security](https://mybb.com/security/) to report possible security concerns or to learn more about security research at MyBB.\n\n### Contact\nThe security team can be reached at [security@mybb.com](mailto:security@mybb.com)."
                }
            ],
            "source": {
                "advisory": "GHSA-v2h7-4jp7-j6hh",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-08-18T17:44:40.432629Z",
                                "id": "CVE-2026-46482",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "yes"
                                    },
                                    {
                                        "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": "2026-08-18T17:46:31.511Z"
                }
            }
        ]
    }
}