CVE-2026-27639
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.28%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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 executed in the browser of any user who views the affected page, including administrators. Version 2026.02.22 fixes the vulnerability.
- CVSS 4.0
- 8.5 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.28% probability · 20th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Affected
- sourcentis/mercator
- Source
- security-advisories@github.com
References
- https://github.com/dbarzin/mercator/commit/839d231399944e43a865198262e96e0218252cc3Patch
- https://github.com/dbarzin/mercator/commit/9902ffd91f287e474729f514c77261f4ef7db8fePatch
- https://github.com/dbarzin/mercator/commit/c58bb1d2fff18605c61d93cfaf77adca416c560aPatch
- https://github.com/dbarzin/mercator/security/advisories/GHSA-65p7-pph2-966gMitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.