Is CVE-2026-45104 actively exploited?

No active exploitation of CVE-2026-45104 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-45104 be exploited remotely?

Yes. CVE-2026-45104 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-45104?

CVE-2026-45104 has a CVSS score of 7.5 (HIGH).

HOME VULNERABILITIESCVE-2026-45104

HIGH

CVE-2026-45104

CWE-129Published: May 27, 2026· Updated: Jun 2, 2026

7.5

CVSS v3.1

EPSS:0.04%probability of exploitation in 30 daysPercentile:12.4th

Official 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.

NVD Source

Technical Analysis

CVE-2026-45104 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.