{"id":"CVE-2026-88862","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-88862","summary":"Capgo (capgo.app) backend through 12.242.4 does not validate parent-child delegation when processing the x-limited-key-id header. checkKeyByIdPg() in supabase/functions/_backend/utils/hono_middleware.ts…","details":"Capgo (capgo.app) backend through 12.242.4 does not validate parent-child delegation when processing the x-limited-key-id header. checkKeyByIdPg() in supabase/functions/_backend/utils/hono_middleware.ts resolves the attacker-supplied numeric API key ID using only the key ID, its expiration state, and the authenticating key's user_id, while hasLimitedRbacSubkeyScope() accepts any key with a non-organization (e.g., app-scoped) RBAC binding and validateSubkeyUser() only compares owning user IDs. Because Capgo treats API keys as independent RBAC principals with separate role bindings, an authenticated apikey_manager API key with no application access can supply the numeric ID of a more privileged same-owner key and have the middleware replace the authenticated principal and effective API-key secret with that key (setSubkeyAuthContext), exercising an app_admin sibling's permissions without knowing or submitting its secret. The issue was reproduced on release 12.242.4 (commit b3d02cdbc23ac59990785acacd1f113c07458568) after the fix for GHSA-8h52-44r7-w343; at the time of the advisory no patched version was available.","published":"2026-09-10T14:17:11.820","modified":"2026-09-10T14:17:11.820","cvss":{"score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":null,"references":[{"type":"WEB","url":"https://github.com/Cap-go/capgo.app/security/advisories/GHSA-5hjr-xhx8-x5j7"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/capgo-api-key-manager-authentication-bypass-via-x-limited-key-id"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-09-10T14:17:11.820"}}