Klaviyo Sign‑Up Bug Exposes User Passwords to Third‑Party Ad Trackers
What Happened — A coding error in Klaviyo’s sign‑up flow caused the password field to be sent to third‑party advertising trackers. Fewer than 200 accounts are known to have been affected, but the flaw potentially allowed external scripts to capture clear‑text passwords.
Why It Matters for Compliance & Audit Readiness
- The incident illustrates a breach of the SOC 2 Privacy principle (CC6.5) where personal data was unintentionally disclosed to an unauthorised party.
- Continuous‑compliance programs must demonstrate that data‑collection points are inventory‑ed, consented to, and that any third‑party integrations are vetted and monitored.
- Verisq’s CookiePLUS Privacy capability provides the audit‑ready evidence (consent logs, DSAR response readiness, and data‑flow mappings) needed to prove that such exposures are prevented and remediated.
Who Is Affected — Email‑marketing SaaS providers, e‑commerce merchants, and any organisations that embed Klaviyo sign‑up widgets on public sites.
Recommended Actions
- Immediately audit all sign‑up forms for inadvertent data leakage to third‑party scripts.
- Map the affected data‑flow to SOC 2 CC6.5 controls and capture remediation evidence for audit.
- Deploy a privacy‑consent framework (e.g., CookiePLUS) to enforce explicit user consent before any tracking code executes.
- Conduct a DSAR readiness check to ensure rapid response if additional accounts are discovered.
Source: TechRepublic – Klaviyo Sign‑Up Password Tracker Exposure
Technical Notes — The bug stemmed from a JavaScript inclusion error that appended the password input to a URL parameter read by ad‑network pixels. No CVE was assigned; the flaw was corrected by Klaviyo within days of discovery.