CVE-2026-40779

Link Library <= 7.8.8 - Authenticated (Contributor+) Arbitrary File Deletion

2026-04-22 00:00
Trương Hữu Phúc (truonghuuphuc)

Strategic Overview

Status
Patched in 7.8.9
Affected Plugin
Link Library
Affected Version
<= 7.8.8
CVSS
8.1High
Weakness type
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVE
CVE-2026-40779
View all Link Library vulnerabilities

At a glance

CVE-2026-40779 is a high-severity Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in the Link Library WordPress plugin, affecting versions <= 7.8.8. It carries a CVSS score of 8.1 (reachable over the network; low attack complexity; high integrity, availability impact). Exploitation requires an authenticated account at Contributor level or above. The issue is fixed in version 7.8.9; sites on affected versions should update now. Disclosed April 2026, reported by Trương Hữu Phúc (truonghuuphuc).

Vulnerability Overview

The Link Library plugin for WordPress is vulnerable to arbitrary file deletion due to insufficient file path validation in all versions up to, and including, 7.8.8. This makes it possible for authenticated attackers, with Contributor-level access and above, to delete arbitrary files on the server, which can easily lead to remote code execution when the right file is deleted (such as wp-config.php).

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on integrity, availability.

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Reaching this weakness in Link Library <= 7.8.8 takes an account at Contributor level or above. Path traversal happens when user-controlled text is used to build a filesystem path without being constrained to an intended directory, so sequences like ../ walk the resolved path somewhere else.

Depending on the operation, it means reading files outside the intended folder — wp-config.php being the usual target — or writing to and deleting paths the web server can touch. For Link Library the fix is 7.8.9: builds <= 7.8.8 are affected, anything from 7.8.9 onward is not.

Remediation

Update to version 7.8.9, or a newer patched version

How does WordSec protect against this?

An attacker needs Contributor access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Link Library 7.8.9 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-40779https://www.wordfence.com/threat-intel/vulnerabilities/id/58f52ad6-02d0-4f34-af04-11c00fdcdae7https://nvd.nist.gov/vuln/detail/CVE-2026-40779

Related records

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