6.1

CVE-2026-42030: mapserver

CVSS: 6.1v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-42030DEBIAN-CVE-2026-42030
Published 08-05-2026Last modified 08-05-2026
Open JSON

Vulnerability summary

CVE-2026-42030 is a medium (CVSS 6.1) vulnerability in mapserver. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 21% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
34/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.1/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.30%
0%100%
Low · +0.05 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Timeline

  1. 08-05-2026
    PublishedVulnerability first disclosed.
  2. 08-05-2026
    Last modifiedVulnerability information updated.

Description

MapServer is a system for developing web-based GIS applications. From version 6.0 to before version 8.6.2, a reflected XSS vulnerability in MapServer's WMS server allows an unauthenticated attacker to inject arbitrary HTML/JavaScript into the browser of any user who opens a crafted WMS URL. The vulnerability is triggered via FORMAT=application/openlayers combined with an unsanitized SRS parameter in WMS 1.3.0 requests. This issue has been patched in version 8.6.2.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.30%

Chance of exploitation in the next 30 days

Percentile

21%

Versus all other CVEs

30-day change

+0.05 pp

From 0.25% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.30%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Mapserver

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • mapserverAll versions (No fix recorded) | < 8.6.2-1
Mapserver1 product
Osgeo1 product
Ubuntu1 product
  • mapserverAll versions (No fix recorded)

4 vendors · 4 products

References

5 links