CVE•Published 2026-05-27•Modified 2026-06-02•0 articles on news•6 live references•NVD data

CVE-2026-45104Osgeo · Mapserver

Vulnerability data via NVD (ingested)

CVSS v3.1

7.5

HIGH

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

EPSS percentile

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Weaknesses (CWE)

CWE-129Improper Validation of Array Index CWE-476NULL Pointer Dereference

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/> — 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.

Timeline

Published 2026-05-27

Modified 2026-06-02

External references

NVD MITRE Exploit-DB GitHub PoC Sploitus VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-45104

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Osgeo Mapserver"

All exposed Osgeo Mapserver instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Mapserver"

HTTP body or banner mentions "Mapserver" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-45104