CVE-2026-102389 Overview
CVE-2026-102389 is a code injection vulnerability in the WPMU DEV Broken Link Checker plugin for WordPress. The flaw affects all versions of broken-link-checker from unspecified early releases through 2.4.14.1. An attacker can trigger improper control of generated code, categorized under [CWE-94], to inject content into a vulnerable WordPress site. Exploitation requires user interaction, such as an administrator visiting a crafted page or link. Successful exploitation impacts the confidentiality of data processed by the plugin.
Critical Impact
Remote attackers can inject arbitrary code into WordPress sites running vulnerable versions of Broken Link Checker, exposing sensitive site data when an authorized user interacts with attacker-controlled input.
Affected Products
- WPMU DEV Broken Link Checker plugin for WordPress
- Versions from initial release through 2.4.14.1
- WordPress sites with the broken-link-checker plugin installed and active
Discovery Timeline
- 2026-10-15 - CVE-2026-102389 published to the National Vulnerability Database (NVD)
- 2026-10-15 - Last updated in NVD database
Technical Details for CVE-2026-102389
Vulnerability Analysis
The Broken Link Checker plugin scans WordPress content for broken hyperlinks and reports results through the administrative interface. The vulnerable code path fails to properly sanitize or validate input that is subsequently interpreted as executable code or markup. This weakness, classified as Improper Control of Generation of Code under [CWE-94], permits content injection within the plugin workflow.
The attack is network-exploitable without authentication but requires user interaction to trigger. Confidentiality impact is rated high because injected payloads can access site data or administrative context. Integrity and availability remain unaffected per the published CVSS vector.
Root Cause
The root cause is insufficient input validation in a code path within broken-link-checker that processes externally influenced content. Attacker-supplied data flows into a sink that generates or evaluates code without adequate sanitization. See the Patchstack CVE Analysis for additional technical context.
Attack Vector
An unauthenticated remote attacker crafts input, such as a malicious URL or page content, that the plugin later processes. When an authenticated user, typically an administrator, interacts with the plugin interface or triggers a scan involving the attacker-controlled content, the injected payload executes within the plugin's context. No prior privileges are required, but user interaction is mandatory.
No verified public exploit code is available at this time. Refer to the Patchstack advisory linked above for responsible technical details.
Stop Remote Code Execution Before It Runs
Singularity™ Endpoint detects and blocks exploit attempts at machine speed, including zero-days and novel attack techniques.
Stop Exploit AttemptsDetection Methods for CVE-2026-102389
Indicators of Compromise
- Unexpected modifications to WordPress posts, pages, or plugin settings tied to Broken Link Checker scan activity
- Outbound HTTP requests from the WordPress host to unfamiliar domains originating from PHP worker processes
- New or modified PHP files in wp-content/plugins/broken-link-checker/ or elsewhere under wp-content/
- Administrative sessions associated with unusual plugin page views immediately preceding anomalous site behavior
Detection Strategies
- Inventory WordPress installations and flag any running broken-link-checker at version 2.4.14.1 or earlier
- Monitor web server access logs for suspicious parameters submitted to Broken Link Checker admin endpoints under /wp-admin/
- Alert on file integrity changes within the plugin directory and the broader WordPress document root
Monitoring Recommendations
- Centralize WordPress and web server logs for correlation across plugin activity, administrator logins, and outbound connections
- Track plugin version drift across managed WordPress properties to detect sites remaining on vulnerable builds
- Review scheduled scan output and admin notifications generated by Broken Link Checker for anomalous content
How to Mitigate CVE-2026-102389
Immediate Actions Required
- Update the Broken Link Checker plugin to the version released after 2.4.14.1 that addresses this issue
- Audit administrator accounts and rotate credentials if suspicious activity is detected
- Review recent plugin scan results and content changes for signs of injected payloads
Patch Information
Consult the Patchstack CVE Analysis for the fixed version information and vendor advisory links. Apply the vendor-supplied update through the WordPress plugin manager or via wp-cli.
Workarounds
- Deactivate and remove the Broken Link Checker plugin until the patched version can be installed
- Restrict access to the WordPress administrative interface by IP allowlist or VPN to reduce the user-interaction attack surface
- Enforce least-privilege for WordPress roles so that fewer accounts can trigger the vulnerable code path
# Update Broken Link Checker to the latest patched release using wp-cli
wp plugin update broken-link-checker
# Verify the installed version is no longer 2.4.14.1 or earlier
wp plugin get broken-link-checker --field=version
# If a patched version is not yet available, deactivate the plugin
wp plugin deactivate broken-link-checker
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
