Vulnerability record · CVE-2026-45104 · published 27 May 2026

CVE-2026-45104: Osgeo mapserver null pointer dereference vulnerability

Osgeo · Mapserver

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/> — 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.

7.5 CVSS 3.1 High EPSS 0.49% · top 60.6% CWE-129 · CWE-129CWE-476 · NULL pointer dereference

7.5CVSS 3.1 base score

0.49%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

1References, 1 tagged exploit

17 Jun 2026Last modified by NVD

Description

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Mapserver Osgeo

References

Link	Tags
https://github.com/MapServer/MapServer/security/advisories/GHSA-4h8g-378q-r75m	ExploitMitigationVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2010-2540Osgeo mapserver permissions and access controls vulnerabilitymapserv.c in mapserv in MapServer before 4.10.6 and 5.x before 5.6.4 does not properly restrict the use of CGI command-line arguments that were inten…EPSS 3.8%2 Aug 2010 10.0CVE-2009-2281Osgeo mapserver memory buffer overflow vulnerabilityMultiple heap-based buffer underflows in the readPostBody function in cgiutil.c in mapserv in MapServer 4.x through 4.10.4 and 5.x before 5.4.2 allow…EPSS 5.9%23 Oct 2009 10.0CVE-2009-0839Osgeo mapserver memory buffer overflow vulnerabilityStack-based buffer overflow in mapserv.c in mapserv in MapServer 4.x before 4.10.4 and 5.x before 5.2.2, when the server has a map with a long IMAGEP…EPSS 9.0%31 Mar 2009 10.0CVE-2009-0840Osgeo mapserver memory buffer overflow vulnerabilityHeap-based buffer underflow in the readPostBody function in cgiutil.c in mapserv in MapServer 4.x before 4.10.4 and 5.x before 5.2.2 allows remote at…EPSS 5.3%31 Mar 2009 10.0CVE-2009-0841Osgeo mapserver path traversal vulnerabilityDirectory traversal vulnerability in mapserv.c in mapserv in MapServer 4.x before 4.10.4 and 5.x before 5.2.2, when running on Windows with Cygwin, a…EPSS 5.3%31 Mar 2009 10.0CVE-2009-1176Osgeo mapserver memory buffer overflow vulnerabilitymapserv.c in mapserv in MapServer 4.x before 4.10.4 and 5.x before 5.2.2 does not ensure that the string holding the id parameter ends in a '\0' char…EPSS 4.1%31 Mar 2009 10.0CVE-2009-1177Osgeo mapserver memory buffer overflow vulnerabilityMultiple stack-based buffer overflows in maptemplate.c in mapserv in MapServer 4.x before 4.10.4 and 5.x before 5.2.2 have unknown impact and remote …EPSS 2.9%31 Mar 2009 9.8CVE-2017-5522Debian linux memory buffer overflow vulnerabilityStack-based buffer overflow in MapServer before 6.0.6, 6.2.x before 6.2.4, 6.4.x before 6.4.5, and 7.0.x before 7.0.4 allows remote attackers to caus…EPSS 4.8%15 Mar 2017

Source: NIST National Vulnerability Database (record CVE-2026-45104), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.