CVE-2026-27639: Mercator is an open source web application designed to enable mapping of information systems

Q: How do I fix CVE-2026-27639?

mercator: upgrade to 2026.02.22. Exact commands for each OS are on this page.

Q: Is CVE-2026-27639 being exploited?

CVE-2026-27639 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-27639 affect?

CVE-2026-27639 affects mercator. Severity is medium (CVSS 5.4). Mercator is an open source web application designed to enable mapping of information systems. A stored Cross-Site Scripting (XSS) vulnerability exists in Mercator prior to version 2026.02.22 due to the use of unescaped Blade directives (`{!

Q: How urgent is CVE-2026-27639?

Priority 25/100. No elevated risk signals yet.

Routine

MEDIUM 5.4UPGRADE

CVE-2026-27639 is a medium-severity flaw (CVSS 5.4) affecting mercator. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Mercator is an open source web application designed to enable mapping of information systems. A stored Cross-Site Scripting (XSS) vulnerability exists in Mercator prior to version 2026.02.22 due to the use of unescaped Blade directives (`{!! !!}`) in display templates. An authenticated user with the User role can inject arbitrary JavaScript payloads into fields such as "contact point" when creating or editing entities. The payload is then execute

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-02-25
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: sourcentis

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-02-25 04:16 UTCPublished CVE record published
2026-06-17 10:27 UTCUpdated Record last modified

sourcentis mercator UPGRADE

Affected: < 2026.02.22

Fixed in: 2026.02.22

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy mercator || rpm -q mercator || mercator --version

2. UPGRADE to 2026.02.22 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mercator

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mercator

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-27639?

mercator: upgrade to 2026.02.22. Exact commands for each OS are on this page.

Is CVE-2026-27639 being exploited?

CVE-2026-27639 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-27639 affect?

CVE-2026-27639 affects mercator. Severity is medium (CVSS 5.4). Mercator is an open source web application designed to enable mapping of information systems. A stored Cross-Site Scripting (XSS) vulnerability exists in Mercator prior to version 2026.02.22 due to the use of unescaped Blade directives (`{!

How urgent is CVE-2026-27639?

Priority 25/100. No elevated risk signals yet.

References

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