{
    "document": {
        "category": "csaf_base",
        "csaf_version": "2.0",
        "distribution": {
            "tlp": {
                "label": "WHITE"
            }
        },
        "lang": "en",
        "notes": [
            {
                "category": "legal_disclaimer",
                "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings."
            }
        ],
        "publisher": {
            "category": "coordinator",
            "contact_details": "cert@ncsc.nl",
            "name": "National Cyber Security Centre",
            "namespace": "https://www.ncsc.nl/"
        },
        "title": "CVE-2026-33541",
        "tracking": {
            "current_release_date": "2026-03-28T07:41:36.977912Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-33541",
            "initial_release_date": "2026-03-26T20:38:38.469990Z",
            "revision_history": [
                {
                    "date": "2026-03-26T20:38:38.469990Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-26T20:40:22.657214Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-03-26T21:27:15.260988Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-26T21:27:21.698275Z",
                    "number": "4",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-27T20:56:44.217008Z",
                    "number": "5",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-03-27T20:56:47.575070Z",
                    "number": "6",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-27T21:26:36.368513Z",
                    "number": "7",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-03-28T07:41:32.360469Z",
                    "number": "8",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (4).| CWES updated (1)."
                },
                {
                    "date": "2026-03-28T07:41:34.782313Z",
                    "number": "9",
                    "summary": "NCSC Score updated."
                }
            ],
            "status": "interim",
            "version": "9"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<34",
                                "product": {
                                    "name": "vers:unknown/<34",
                                    "product_id": "CSAFPID-5919185"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "TSPortal"
                    }
                ],
                "category": "vendor",
                "name": "miraheze"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-33541",
            "cwe": {
                "id": "CWE-770",
                "name": "Allocation of Resources Without Limits or Throttling"
            },
            "notes": [
                {
                    "category": "description",
                    "text": "TSPortal is the WikiTide Foundation’s in-house platform used by the Trust and Safety team to manage reports, investigations, appeals, and transparency work. Prior to version 34, a flaw in TSPortal allowed attackers to create arbitrary user records in the database by abusing validation logic. While validation correctly rejected invalid usernames, a side effect within a validation rule caused user records to be created regardless of whether the request succeeded. This could be exploited to cause uncontrolled database growth, leading to a potential denial of service (DoS). Version 34 contains a fix for the issue.",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33541.json"
                },
                {
                    "category": "description",
                    "text": "TSPortal is the WikiTide Foundation’s in-house platform used by the Trust and Safety team to manage reports, investigations, appeals, and transparency work. Prior to version 34, a flaw in TSPortal allowed attackers to create arbitrary user records in the database by abusing validation logic. While validation correctly rejected invalid usernames, a side effect within a validation rule caused user records to be created regardless of whether the request succeeded. This could be exploited to cause uncontrolled database growth, leading to a potential denial of service (DoS). Version 34 contains a fix for the issue.",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33541"
                },
                {
                    "category": "description",
                    "text": "### Summary\nA flaw in TSPortal allowed attackers to create arbitrary user records in the database by abusing validation logic. While validation correctly rejected invalid usernames, a side effect within a validation rule caused user records to be created regardless of whether the request succeeded. This could be exploited to cause uncontrolled database growth, leading to a potential denial of service (DoS).\n\n### Details\nWhen submitting a Data Processing Agreement (DPA) request in TSPortal, the `DPAAlreadyLive` validation rule previously called `User::findOrCreate()`.\n\nThis method created a user record if one did not already exist.\n\nAlthough username validation (via `MirahezeUsernameRule`) correctly rejected invalid usernames, the `DPAAlreadyLive` rule was still executed during validation. Because it performed a state-changing operation, it created user records even when the overall validation failed and no DPA was created.\n\nAs a result:\n- Validation correctly rejected invalid input\n- However, user records were still inserted into the database as a side effect\n\nThese records were created:\n- Without a successful DPA request\n- Without audit logging tied to a completed action\n- Without visibility into their origin\n\n### Impact\nAn attacker could exploit this behavior by automating requests with invalid usernames, resulting in:\n\n- Mass creation of arbitrary user records\n- Unbounded database growth\n- Increased storage and indexing overhead\n- Potential degradation of application performance\n\nAt scale, this could lead to a denial of service condition due to resource exhaustion.\n\n### Proof of Concept\n1. Submit a DPA request using an invalid username\n2. Ensure the request fails validation due to `MirahezeUsernameRule`\n3. Observe that a corresponding user record is still created in the database\n\nThis behavior was confirmed prior to remediation.\n\n### Root Cause\nThe issue stemmed from:\n- Performing state-changing operations (`findOrCreate`) inside validation logic\n- Validation rules executing regardless of overall validation success\n- Lack of separation between validation and persistence layers\n\n### Mitigation\nThe issue has been fixed by removing database write operations from validation logic.\n\nSpecifically:\n- Replaced `User::findOrCreate()` with a non-mutating lookup (`User::firstWhere(...)`)\n- Ensured validation rules only perform read operations\n- Prevented user creation unless all validation passes",
                    "title": "github - https://api.github.com/advisories/GHSA-f346-8rp3-4h9h"
                },
                {
                    "category": "other",
                    "text": "0.00039",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "4.1",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "Is related to CWE-400 (Uncontrolled Resource Consumption)",
                    "title": "NCSC Score top increasing factors"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5919185"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33541.json"
                },
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33541"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://api.github.com/advisories/GHSA-f346-8rp3-4h9h"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd",
                    "url": "https://github.com/miraheze/TSPortal/security/advisories/GHSA-f346-8rp3-4h9h"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33541"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://issue-tracker.miraheze.org/T15115"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/advisories/GHSA-f346-8rp3-4h9h"
                }
            ],
            "scores": [
                {
                    "cvss_v3": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
                        "baseScore": 6.5,
                        "baseSeverity": "MEDIUM"
                    },
                    "products": [
                        "CSAFPID-5919185"
                    ]
                }
            ],
            "title": "CVE-2026-33541"
        }
    ]
}