{
    "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-2026-33721",
        "tracking": {
            "current_release_date": "2026-04-02T15:04:24.788218Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-33721",
            "initial_release_date": "2026-03-27T00:38:41.912814Z",
            "revision_history": [
                {
                    "date": "2026-03-27T00:38:41.912814Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (2).| CWES updated (1)."
                },
                {
                    "date": "2026-03-27T00:38:47.287717Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-03-27T01:24:56.180465Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)."
                },
                {
                    "date": "2026-03-27T01:25:06.071305Z",
                    "number": "4",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-27T07:35:35.583203Z",
                    "number": "5",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-27T19:41:38.114334Z",
                    "number": "6",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (4).| CWES updated (1).| Vendor_assessment created."
                },
                {
                    "date": "2026-03-27T19:41:42.149667Z",
                    "number": "7",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-27T20:56:24.107235Z",
                    "number": "8",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-03-27T20:56:25.799885Z",
                    "number": "9",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-28T12:44:15.501456Z",
                    "number": "10",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| Products connected (2)."
                },
                {
                    "date": "2026-03-30T12:41:46.386900Z",
                    "number": "11",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-04-01T18:28:01.840789Z",
                    "number": "12",
                    "summary": "Products created (1).| Product Identifiers created (1).| Exploits created (1)."
                },
                {
                    "date": "2026-04-01T18:28:03.700613Z",
                    "number": "13",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-02T15:00:25.813973Z",
                    "number": "14",
                    "summary": "EPSS updated."
                },
                {
                    "date": "2026-04-02T15:00:31.895041Z",
                    "number": "15",
                    "summary": "NCSC Score updated."
                }
            ],
            "status": "interim",
            "version": "15"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/>=4.2|<8.6.1",
                                "product": {
                                    "name": "vers:unknown/>=4.2|<8.6.1",
                                    "product_id": "CSAFPID-5920666"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "MapServer"
                    }
                ],
                "category": "vendor",
                "name": "MapServer"
            },
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/>=4.2.0|<8.6.1",
                                "product": {
                                    "name": "vers:unknown/>=4.2.0|<8.6.1",
                                    "product_id": "CSAFPID-5982379",
                                    "product_identification_helper": {
                                        "cpe": "cpe:2.3:a:osgeo:mapserver:*:*:*:*:*:*:*:*"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "MapServer"
                    }
                ],
                "category": "vendor",
                "name": "OSGeo"
            },
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:deb/unknown",
                                        "product": {
                                            "name": "vers:deb/unknown",
                                            "product_id": "CSAFPID-3128342"
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "mapserver"
                            }
                        ],
                        "category": "product_family",
                        "name": "bookworm"
                    },
                    {
                        "branches": [
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:deb/unknown",
                                        "product": {
                                            "name": "vers:deb/unknown",
                                            "product_id": "CSAFPID-1398473"
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "mapserver"
                            }
                        ],
                        "category": "product_family",
                        "name": "bullseye"
                    }
                ],
                "category": "vendor",
                "name": "Debian"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-33721",
            "cwe": {
                "id": "CWE-787",
                "name": "Out-of-bounds Write"
            },
            "notes": [
                {
                    "category": "description",
                    "text": "MapServer is a system for developing web-based GIS applications. Starting in version 4.2 and prior to version 8.6.1, a heap-buffer-overflow write in MapServer’s SLD (Styled Layer Descriptor) parser lets a remote, unauthenticated attacker crash the MapServer process by sending a crafted SLD with more than 100 Threshold elements inside a ColorMap/Categorize structure (commonly reachable via WMS GetMap with SLD_BODY). Version 8.6.1 patches the issue.",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33721.json"
                },
                {
                    "category": "description",
                    "text": "MapServer is a system for developing web-based GIS applications. Starting in version 4.2 and prior to version 8.6.1, a heap-buffer-overflow write in MapServer’s SLD (Styled Layer Descriptor) parser lets a remote, unauthenticated attacker crash the MapServer process by sending a crafted SLD with more than 100 Threshold elements inside a ColorMap/Categorize structure (commonly reachable via WMS GetMap with SLD_BODY). Version 8.6.1 patches the issue.",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33721"
                },
                {
                    "category": "description",
                    "text": "A flaw was found in MapServer, a system for developing web-based Geographic Information System (GIS) applications. A remote, unauthenticated attacker can exploit a heap-buffer-overflow vulnerability by sending a specially crafted Styled Layer Descriptor (SLD) with an excessive number of Threshold elements. This can cause the MapServer process to crash, leading to a Denial of Service (DoS).\nThis is an Important denial of service vulnerability in MapServer, a system for developing web-based GIS applications. A remote, unauthenticated attacker can trigger a heap-buffer-overflow by sending a specially crafted Styled Layer Descriptor (SLD) with an excessive number of Threshold elements, causing the MapServer process to crash. This affects Red Hat Community Projects that include MapServer versions prior to 8.6.1.",
                    "title": "redhat - https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-33721.json"
                },
                {
                    "category": "description",
                    "text": "MapServer is a system for developing web-based GIS applications. Starting in version 4.2 and prior to version 8.6.1, a heap-buffer-overflow write in MapServer’s SLD (Styled Layer Descriptor) parser lets a remote, unauthenticated attacker crash the MapServer process by sending a crafted SLD with more than 100 Threshold elements inside a ColorMap/Categorize structure (commonly reachable via WMS GetMap with SLD_BODY). Version 8.6.1 patches the issue.",
                    "title": "debian - https://security-tracker.debian.org/tracker/CVE-2026-33721"
                },
                {
                    "category": "other",
                    "text": "0.0021",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "4.2",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "There is exploit data available from source Nvd",
                    "title": "NCSC Score top decreasing factors"
                },
                {
                    "category": "details",
                    "text": "Severity: 3\n",
                    "title": "Vendor assessment"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5920666",
                    "CSAFPID-1398473",
                    "CSAFPID-3128342",
                    "CSAFPID-5982379"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33721.json"
                },
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33721"
                },
                {
                    "category": "external",
                    "summary": "Source - redhat",
                    "url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-33721.json"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Source - debian",
                    "url": "https://security-tracker.debian.org/tracker/CVE-2026-33721"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd; redhat",
                    "url": "https://github.com/MapServer/MapServer/security/advisories/GHSA-cv4m-mr84-fgjp"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd; redhat",
                    "url": "https://github.com/MapServer/MapServer/releases/tag/rel-8-6-1"
                },
                {
                    "category": "external",
                    "summary": "Reference - redhat",
                    "url": "https://www.cve.org/CVERecord?id=CVE-2026-33721"
                },
                {
                    "category": "external",
                    "summary": "Reference - redhat",
                    "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33721"
                }
            ],
            "scores": [
                {
                    "cvss_v3": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                        "baseScore": 7.5,
                        "baseSeverity": "HIGH"
                    },
                    "products": [
                        "CSAFPID-1398473",
                        "CSAFPID-3128342",
                        "CSAFPID-5920666",
                        "CSAFPID-5982379"
                    ]
                }
            ],
            "title": "CVE-2026-33721"
        }
    ]
}