{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-43938",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-05-04T16:59:09.089Z",
        "datePublished": "2026-05-12T13:57:56.951Z",
        "dateUpdated": "2026-05-12T15:39:46.446Z"
    },
    "containers": {
        "cna": {
            "title": "YAF.NET: Unauthenticated Stored Second-Order XSS in Admin Event Log via Reflected `User-Agent` Header",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-79",
                            "lang": "en",
                            "description": "CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-80",
                            "lang": "en",
                            "description": "CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-116",
                            "lang": "en",
                            "description": "CWE-116: Improper Encoding or Escaping of Output",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 8.1,
                        "baseSeverity": "HIGH",
                        "confidentialityImpact": "HIGH",
                        "integrityImpact": "HIGH",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "REQUIRED",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/YAFNET/YAFNET/security/advisories/GHSA-33gv-fc78-qgf5",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/YAFNET/YAFNET/security/advisories/GHSA-33gv-fc78-qgf5"
                }
            ],
            "affected": [
                {
                    "vendor": "YAFNET",
                    "product": "YAFNET",
                    "versions": [
                        {
                            "version": ">= 4.0.0-beta.1, < 4.0.5",
                            "status": "affected"
                        },
                        {
                            "version": "< 3.2.12",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-05-12T13:57:56.951Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "YetAnotherForum.NET (YAF.NET) is a C# ASP.NET forum. Prior to 4.0.5 and 3.2.12, the application's database logger (YAFNET.Core/Logger/DbLogger.cs) captures the incoming request's User-Agent header into a JObject, serializes it with JsonConvert, and stores the result in the EventLog.Description column whenever an event (e.g., an unhandled exception) is logged. The admin event-log page (YetAnotherForum.NET/Pages/Admin/EventLog.cshtml.cs) later deserializes that JSON in FormatStackTrace() and interpolates the UserAgent value directly into an HTML string with no encoding, and the Razor view EventLog.cshtml emits the result through @Html.Raw. This vulnerability is fixed in 4.0.5 and 3.2.12."
                }
            ],
            "source": {
                "advisory": "GHSA-33gv-fc78-qgf5",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/YAFNET/YAFNET/security/advisories/GHSA-33gv-fc78-qgf5",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-05-12T15:39:17.598324Z",
                                "id": "CVE-2026-43938",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-05-12T15:39:46.446Z"
                }
            }
        ]
    }
}