Broken Link Checker plain-permalink variables permit unauthenticated code execution
Broken Link Checker before 2.4.12 does not constrain query variables accepted from unauthenticated requests on sites using plain permalinks. An attacker can overwrite arbitrary PHP global variables; when a classic, non-block theme is active, the resulting state can execute arbitrary server-side code.
- Component
- Broken Link Checker
- Plugin slug
broken-link-checker- Affected
- < 2.4.12
- Safe version
2.4.12- Published
- Aug 19, 2026
This CVE was published Aug 19, 2026 and is one of 15 known issues for this plugin.
Update, patch or deactivate.
Update Broken Link Checker to 2.4.12 or later. Until updated, avoid plain permalinks with a classic theme or disable the plugin, and investigate the site if exploitation is suspected.
A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical description
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.
CVE / CNA vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H