MapServer: NULL pointer dereference in SLD `` rule parsing reachable via WMS `SLD_BODY`_CVE-2026-45104

{
    "lastseen": "",
    "description": "MapServer is a system for developing web-based GIS applications. From 6.4.0 to before 8.6.3, msSLDParseUserStyle always calls _SLDApplyRuleValues(psRule, psLayer, 1); for any <Rule> carrying <ElseFilter/> \u2014 it assumes msSLDParseRule added one class. When the rule has no symbolizer (a structurally valid SLD), msSLDParseRule adds zero, and _SLDApplyRuleValues ends up indexing _class[-1], resulting in a NULL pointer dereference. A 200-byte well-formed SLD via the WMS SLD_BODY= parameter is enough to trigger this, no auth required. This vulnerability is fixed in 8.6.3.",
    "published": "2026-05-27T18:41:39.396Z",
    "modified": "2026-05-27T18:41:39.396Z",
    "type": "cve",
    "title": "MapServer: NULL pointer dereference in SLD `<ElseFilter>` rule parsing reachable via WMS `SLD_BODY`",
    "source": "GitHub_M",
    "references": "https://github.com/MapServer/MapServer/security/advisories/GHSA-4h8g-378q-r75m",
    "id": "CVE-2026-45104",
    "bulletinFamily": "",
    "cwe": [
        "CWE-129",
        "CWE-476"
    ],
    "cvelist": null,
    "sourceData": "MapServer MapServer >= 6.4.0, < 8.6.3",
    "sourceHref": "",
    "cvss": {
        "score": 7.5,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "MapServer",
    "version": ">= 6.4.0, < 8.6.3",
    "vendor": "MapServer",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
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    "ai_score": 0
}