{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "MapServer",
          "vendor": "MapServer",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 6.4.0, \u003c 8.6.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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 \u003cRule\u003e carrying \u003cElseFilter/\u003e \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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-129",
              "description": "CWE-129: Improper Validation of Array Index",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-476",
              "description": "CWE-476: NULL Pointer Dereference",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-27T18:41:39.396Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/MapServer/MapServer/security/advisories/GHSA-4h8g-378q-r75m",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/MapServer/MapServer/security/advisories/GHSA-4h8g-378q-r75m"
        }
      ],
      "source": {
        "advisory": "GHSA-4h8g-378q-r75m",
        "discovery": "UNKNOWN"
      },
      "title": "MapServer: NULL pointer dereference in SLD `\u003cElseFilter\u003e` rule parsing reachable via WMS `SLD_BODY`"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-45104",
    "datePublished": "2026-05-27T18:41:39.396Z",
    "dateReserved": "2026-05-08T19:27:26.699Z",
    "dateUpdated": "2026-05-27T18:41:39.396Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-45104",
      "date": "2026-05-29",
      "epss": "0.0004",
      "percentile": "0.12504"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-45104\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-05-27T20:16:38.407\",\"lastModified\":\"2026-05-29T16:25:57.843\",\"vulnStatus\":\"Undergoing Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"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 \u003cRule\u003e carrying \u003cElseFilter/\u003e \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.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"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\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-129\"},{\"lang\":\"en\",\"value\":\"CWE-476\"}]}],\"references\":[{\"url\":\"https://github.com/MapServer/MapServer/security/advisories/GHSA-4h8g-378q-r75m\",\"source\":\"security-advisories@github.com\"}]}}"
  }
}