Nexter Blocks - Path Traversal (CVE-2026-15420)

CVE-2026-15420

Vulnerability CVE-2026-15420 PLUGIN nexter-blocks MEDIUM

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.

CVE-2026-15420

MEDIUM CVSS 4.3 Published 2026-07-24 Updated 2026-07-24

AI Risk Moderate (46/100) Active Exploit: No strong signal Published Exploit: No public exploit references Priority: P4 Planned

Severity Band MEDIUM

CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Affected Components 1

Reference Links 10

AI Risk Engine Moderate (46/100)

Exploitability High

Active Exploitation No strong signal

Published Exploit Status No public exploit references

Threat Timeline

2026-07-24 CVE published and first recorded in the threat feed.
2026-07-24 Record updated with latest vulnerability metadata.
2026-07-26 AI technical context refreshed for mitigation and impact guidance.
Now Monitoring for follow-up changes, linked references, and new related CVEs.

AI Context

Machine-generated threat intelligence

AI Updated 75 days ago

AI enriched 75 days ago (2026-07-26 17:38 UTC)

Technical Summary

Potential Impact

Severity is MEDIUM (CVSS 4.3). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as High based on remote code execution potential.

Primary risk drivers: remote code execution potential

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

AI risk score 46/100 (Moderate, High) with priority P4 Planned. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

Affected Products

Nexter Blocks PLUGIN · nexter-blocks Affected range not specified Fixed version not specified

References

What to do about this

Patch on your next cycle Worth fixing, but not ahead of other work.

Fix it

Update Nexter Blocks to the latest available version.

Where the vendor has not published a fix yet, disable the plugin until they do.

Cannot update today? Request / payload inspection (WAF) in Hack Halt ProSecure blocks this class of attack before WordPress processes the request.

Inspect request parameters and bodies for injection, traversal and file-inclusion payloads, and refuse the request rather than logging it.

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Not sure if you are affected?

Scan your site to see whether it runs Nexter Blocks, and at which version.

Free, no installation, no account. It reads what your site already publishes, then tells you which plugins carry known vulnerabilities and what to do about each one.

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Am I affected by this vulnerability?

You are affected if your site runs Nexter Blocks.

How do I fix it?

Update Nexter Blocks to the latest available version. Where the vendor has not yet published a fix, remove or disable the plugin until they do. Until you can update, Request / payload inspection (WAF) in Hack Halt ProSecure contains this class of attack at the request layer.

What can an attacker actually do?

This is a Path Traversal flaw. An attacker who exploits it can read files outside the intended directory, including wp-config.php.