{"id":"CVE-2026-45104","summary":"MapServer: NULL pointer dereference in SLD `\u003cElseFilter\u003e` rule parsing reachable via WMS `SLD_BODY`","details":"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 — 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.","aliases":["GHSA-4h8g-378q-r75m"],"modified":"2026-07-08T08:13:30.333907597Z","published":"2026-05-27T18:41:39.396Z","related":["openSUSE-SU-2026:20857-1"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-129","CWE-476"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45104.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45104.json"},{"type":"ADVISORY","url":"https://github.com/MapServer/MapServer/security/advisories/GHSA-4h8g-378q-r75m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45104"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mapserver/mapserver","events":[{"introduced":"a098e546885dd7244ce6174ec11e6f0410879a41"},{"fixed":"d83a1b9ce1301e6f941a1a8ea787fd209f7ecfba"}],"database_specific":{"source":["AFFECTED_FIELD","CPE_RANGE"],"cpe":"cpe:2.3:a:osgeo:mapserver:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"6.4.0"},{"fixed":"8.6.3"}]}}],"versions":["rel-8-6-2","rel-8-6-1","rel-8-6-0","rel-8-6-0-rc1","rel-8-6-0-beta2","rel-8-6-0-beta1","rel-6-4-0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45104.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}