CVE-2026-56244 Capgo CVE debrief

Who should care

Defenders responsible for securing webhook integrations, especially in environments where webhook security is crucial, should assess exposure and prioritize remediation. This includes reviewing webhook configurations, updating security policies, and ensuring that all API keys are properly secured. Additionally, defenders should verify that webhook receivers are validated and configured securely to prevent exploitation.

Why it matters

CVE-2026-56244 is a high-severity vulnerability in Capgo that allows non-admin API keys to read webhook signing secrets, breaking webhook authenticity and integrity. Defenders responsible for securing webhook integrations should assess exposure and prioritize remediation.

• Webhook authenticity and integrity are compromised, allowing attackers to send forged events.
• Defenders must verify exposure and remediate the vulnerability to prevent exploitation.
• API key permissions and row-level security policies require review and updates.
• Webhook event monitoring is necessary to detect suspicious activity.

Technical summary

The vulnerability in Capgo allows non-admin API keys to read webhook signing secrets via Supabase REST due to insufficient row-level security policies on the webhooks table. This issue enables attackers to retrieve the webhook secret and forge valid X-Capgo-Signature headers to send authenticated webhook events to configured receivers, breaking webhook authenticity and integrity. The vulnerability has a high CVSS score of 7.1 and is considered a high-severity issue. Defenders should prioritize verifying exposure and remediating this vulnerability, especially in environments where webhook security is crucial. The CVE record and NVD entry provide details on the vulnerability, including its description, CVSS score

Defensive priority

Defenders should prioritize verifying exposure and remediating this vulnerability, especially in environments where webhook security is crucial.

Recommended defensive actions

• Verify exposure by checking if non-admin API keys have access to webhook signing secrets.
• Remediate the vulnerability by updating row-level security policies on the webhooks table.
• Monitor webhook events for suspicious activity.
• Review and update API key permissions to prevent unauthorized access.
• Implement additional logging and monitoring to detect potential exploitation.
• Conduct a thorough review of webhook configurations and security policies.
• Ensure that all webhook receivers are validated and configured securely.

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description, CVSS score, and affected product. However, the corpus does not establish versions, exploitation, impact, or remediation, which require verification from the supplied official sources.

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.