What’s Vulnerable › Vulnerabilities

CVE-2026-55826: Customer Order Data Exposed via Unauthenticated gtm_server_side_order_id Cookie Manipulation in GTM Server Side WordPress Plugin

• Severity: high (CVSS 8.7 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-23 · updated 2026-10-29
• Weakness: CWE-200

Description

The GTM Server Side plugin by stape.io implements server-side tracking on WordPress websites. From version 2.0.0 to before version 2.1.48, the WooCommerce purchase event tracking mechanism allows an unauthenticated attacker to trigger the rendering of another customer's full order data — including personally identifiable information (PII) — into the page's JavaScript dataLayer. This issue has been patched in version 2.1.48.

Affected products

• stape-io gtm-server-side-wordpress-plugin: from 2.0.0, < 2.1.48

References

• http://github.com/stape-io/gtm-server-side-wordpress-plugin/tree/v2.1.47
• https://github.com/stape-io/gtm-server-side-wordpress-plugin/commit/702898f57772279ca63d3f800336c1803103ea41
• https://github.com/stape-io/gtm-server-side-wordpress-plugin/commit/9ff46a050028c40fad5416f2fa35be574c823434
• https://github.com/stape-io/gtm-server-side-wordpress-plugin/releases/tag/2.1.48
• https://github.com/stape-io/gtm-server-side-wordpress-plugin/security/advisories/GHSA-j5j2-gr8c-8rvf
• https://github.com/stape-io/gtm-server-side-wordpress-plugin/tree/v2.1.48

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