CVE-2026-56245 Cap-go CVE debrief

Who should care

Defenders responsible for Supabase Capgo deployments, especially those using versions prior to 12.128.2, should assess exposure to this vulnerability and verify the potential impact on billing and quota data.

Why it matters

CVE-2026-56245 is an authorization bypass vulnerability in Supabase Capgo before version 12.128.2, allowing unauthenticated attackers to insert arbitrary build-time records. Defenders should prioritize verifying exposure, assessing potential impact on billing and quota data, and updating to version 12.128.2 or later. The corpus does not establish versions, exploitation, impact, or remediation beyond the provided information, requiring verification from official sources.

• Potential resource exhaustion due to arbitrary build-time record insertion
• Cross-tenant billing manipulation through poisoned billing and quota data
• Need for verification of exposure and impact in Supabase Capgo deployments prior to version 12.128.2
• Priority on updating to version 12.128.2 or later to mitigate the vulnerability

Technical summary

The vulnerability is located in the SECURITY DEFINER record_build_time RPC function of Supabase Capgo before version 12.128.2. This function allows unauthenticated attackers to insert arbitrary build-time records by calling POST /rest/v1/rpc/record_build_time with a public API key. The potential impact includes resource exhaustion and cross-tenant billing manipulation. Defenders should prioritize verifying exposure to this vulnerability, especially if using Supabase Capgo versions prior to 12.128.2, and assess the potential impact on billing and quota data.

Defensive priority

Defenders should prioritize verifying exposure to this vulnerability, especially if using Supabase Capgo versions prior to 12.128.2, and assess the potential impact on billing and quota data.

Recommended defensive actions

• Verify exposure to this vulnerability, especially if using Supabase Capgo versions prior to 12.128.2
• Assess the potential impact on billing and quota data
• Update to version 12.128.2 or later if vulnerable
• Monitor for suspicious activity related to the record_build_time RPC function
• 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

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its CVSS score of 8.8 and severity of HIGH. However, the corpus does not establish versions, exploitation, impact, or remediation beyond the provided information.

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.