WHMCS 8.13.1 Security Update
Honour parent theme definition for captcha.tpl on Login as Owner link
Default Update CMD
Update WHMCS to the latest version via the Admin Area (Utilities > Update WHMCS).What this means under a SharedLicense license
Your SharedLicense license itself is not affected — this is a change in WHMCS software, not in licensing. Apply it on every affected server: update to the fixed release from the WHMCS Admin Area. Licenses keep working through updates; nothing needs re-issuing or re-activating.
8.13.1 (Maintenance) Security Fixes
WHMCS 8.13.1 is a security maintenance release. It bundles a number of security hardening changes. Below is an explanation of what each fix addresses, along with the affected versions and the update path.
Honour parent theme definition for captcha.tpl on Login as Owner link
The login-as-owner flow now respects the parent theme’s CAPTCHA template definition, closing a gap where the CAPTCHA could be skipped.
Undisclosed Security Fix
WHMCS ships several security fixes each release without publishing technical detail. These are applied as hardening of the platform and are not accompanied by a public CVE, so the specific mechanism is withheld to protect installations that have not yet updated. Upgrading is the recommended course of action.
Affected Versions and Remediation
Apply the update to the latest patch release of your WHMCS branch. WHMCS supports updating in place through the Admin Area (Utilities > Update WHMCS) or by uploading the release package. Back up both your WHMCS files and database before updating.
References
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