{"id":"CVE-2026-58202","title":"OpenReception: Confirmation-email links built from the request Host enable pending-account takeover via `POST /api/auth/resend-confirmation`","summary":"OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 2.0.0, the account-confirmation link in emails is built from the request Host header, with no allowlist. The una…","severity":"high","cvss":8.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L","cvssSource":"cna","cwe":["CWE-640"],"vendor":"open-reception","product":"appointment-booking-software","affected":["appointment-booking-software < 2.0.0"],"published":"2026-10-23","updated":"2026-10-23","sourceUpdated":"2026-10-23T20:27:36.090Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-58202","references":[{"url":"https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-w5g9-g2p4-2g4m","label":"https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-w5g9-g2p4-2g4m"},{"url":"https://github.com/open-reception/appointment-booking-software/commit/df5432776a1a5b47c3a64d64e9d05dbe2b7a7819","label":"https://github.com/open-reception/appointment-booking-software/commit/df5432776a1a5b47c3a64d64e9d05dbe2b7a7819"},{"url":"https://github.com/open-reception/appointment-booking-software/releases/tag/v2.0.0","label":"https://github.com/open-reception/appointment-booking-software/releases/tag/v2.0.0"}],"tags":["cve.org"],"ingestedAt":"2026-10-23T21:38:13.060Z","slug":"CVE-2026-58202","body":"## Overview\n\nOpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 2.0.0, the account-confirmation link in emails is built from the request Host header, with no allowlist. The unauthenticated POST /api/auth/resend-confirmation rotates a pending invitee's confirmation token and emails a link whose host comes from the request. An attacker who sends one resend-confirmation with Host: attacker.example and a pending invitee's email causes that invitee to receive a confirmation email whose only link points to the attacker. If the invitee clicks, the one-time confirmation token reaches the attacker, who then confirms the account on the real tenant domain and registers a passkey they control, taking over the account before the legitimate invitee ever uses it. All released versions through v1.1.0 are affected; no patched version exists yet. Reaching the app with a spoofed Host depends on the front proxy: the stock Caddy catch-all forwards it, while an operator who configures explicit per-tenant proxy blocks is not affected (see Details 4). The invite path builds links from the trusted tenant.domain (invite/+server.ts:204-210); the resend-confirmation path builds them from the request Host. This issue has been patched in version 2.0.0.\n\n## Affected\n\n- `appointment-booking-software < 2.0.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":46,"depthScoreParts":{"impact":45.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}