Is CVE-2026-45104 in the CISA KEV catalog?

No. CVE-2026-45104 is not currently on the CISA Known Exploited Vulnerabilities list.

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

CVE-2026-45104 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2026-45104?

CVE-2026-45104 has an EPSS score of 0.32% (24th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-45104

HIGH

7.5

CVSS v3

NVD

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.

CWE-129 CWE-476NULL Pointer Dereference

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

0.32%probability of exploitation in 30 days

24thpercentile

Low risk: more likely to be exploited than 24% of all known CVEs.

References

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

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-02.