CVE-2026-55826 stape-io CVE debrief

Who should care

Defenders responsible for WordPress websites using the GTM Server Side plugin, particularly those handling customer order data, should assess exposure and prioritize patching. This includes security teams, vulnerability management teams, and operators responsible for maintaining WordPress deployments. They should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance, and plan vendor-supported updates或

Why it matters

Defenders should care about CVE-2026-55826 because it allows unauthenticated attackers to access customer order data, including PII, on affected WordPress websites. Patching to version 2.1.48 or later is crucial to prevent potential data exposure.

• Potential exposure of customer order data
• Risk of personally identifiable information (PII) disclosure
• Need for patching to prevent unauthorized data access
• Verification of affected versions and exposure required

Technical summary

The GTM Server Side plugin by stape.io implements server-side tracking on WordPress websites. A vulnerability in versions 2.0.0 to before 2.1.48 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 arises from the WooCommerce purchase event tracking mechanism, which does not properly validate the gtm_server_side_order_id cookie. As a result, defenders should prioritize patching to version 2.1.48 or later and verify the affected versions to assess exposure.

Defensive priority

Defenders should prioritize patching to version 2.1.48 or later, verify and limit exposure of affected versions, and monitor for potential misuse.

Recommended defensive actions

• Patch to version 2.1.48 or later
• Verify and limit exposure of affected versions
• Monitor for potential misuse
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE Program record and NVD vulnerability detail provide official information on the vulnerability. Supplemental sources include GitHub advisories and commits related to the patch. Defenders should verify the affected versions, assess exposure, and prioritize patching to version 2.1.48 or later. Evidence of the vulnerability includes the unauthenticated gtm_server_side_order_id cookie manipulation and the rendering of another customer's full order data into the page's JavaScript dataLayer.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.