What is CVE-2026-18937?

CVE-2026-18937 is a critical-severity vulnerability in Broken Link Checker, classified under Code Injection. CVSS score: 9.0/10. Published 2026-08-19.

How severe is CVE-2026-18937?

Critical severity. CVSS v3 base score is 9.0 out of 10.

RCE in Broken Link Checker

CVE-2026-18937

The Broken Link Checker WordPress plugin before 2.4.12 does not limit which query variables it accepts from user input on sites using plain permalinks, allowing unauthenticated users to overwrite arbitrary PHP global variables, and to execute arbitrary code on the server when a classic (non-block) is active.

Vulnerability class: RCE (Remote Code Execution)

CVSS v3 metric

CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Unknown Broken Link Checker

Weakness classification (CWE)

CWE-94 — Code Injection

References

contact@wpscan.com (technical-description, exploit, vdb-entry)

Frequently asked questions

What is CVE-2026-18937?: CVE-2026-18937 is a critical-severity vulnerability in Broken Link Checker, classified under Code Injection. CVSS score: 9.0/10. Published 2026-08-19.
How severe is CVE-2026-18937?: Critical severity. CVSS v3 base score is 9.0 out of 10.