{"id":"CVE-2026-50554","aliases":["GHSA-588f-fvcv-xhvf","GO-2026-5948"],"url":"https://o3.security/vulnerability/CVE-2026-50554","summary":"Note Mark: Unauthenticated disclosure of soft-deleted note metadata via deleted=true on public books in note-mark","details":"Summary\n\n GET /api/books/{bookID}/notes is an unauthenticated endpoint that accepts a \"deleted\" query parameter. When the request is ?deleted=true, the\n service runs the query with Unscoped() (bypassing GORM's soft-delete scope) but keeps the read-authorization clause as \"owner_id = ? OR is_public\n = ?\". As a result, any unauthenticated caller can enumerate the metadata of soft-deleted (\"trashed\") notes belonging to any public book — notes\n the owner explicitly deleted and expected to be removed from public view.\n\n Affected component (code-verified)\n\n backend/services/notes.go — GetNotesByBookID (lines 72-89):\n\n func (s NotesService) GetNotesByBookID(currentUserID *uuid.UUID, bookID uuid.UUID, deleted bool) ([]db.Note, error) {\n tx := db.DB\n if deleted {\n tx = tx.Unscoped() // <-- bypasses soft-delete scope\n }\n tx = tx.\n Preload(\"Book\").\n Joins(\"JOIN books ON books.id = notes.book_id\").\n Where(\n db.DB.Where(\"books.id = ?\", bookID),\n db.DB.Where(\"owner_id = ? OR is_public = ?\", currentUserID, true), // <-- is_public still honored for trash\n )\n if deleted {\n tx = tx.Where(\"notes.deleted_at IS NOT NULL\")\n }\n var notes []db.Note\n return notes, dbErrorToServiceError(tx.Find(¬es).Error)\n }\n\n Route registration confirms the endpoint has no AuthRequiredMiddleware (backend/handlers/notes.go:37), and the deleted flag is attacker-controlled\n (backend/handlers/notes.go:86 — Deleted bool with query:\"deleted\").\n\n Proof of concept\n\n 1. A victim owns a public book (is_public = true), creates a note, then soft-deletes it (moves it to trash). The note still exists in the DB with\n deleted_at set.\n 2. An unauthenticated attacker who knows (or enumerates) the book UUID requests: GET /api/books//notes?deleted=true\n 3. The response lists the soft-deleted note(s) — id, title, slug, timestamps — even though the attacker is not authenticated and the owner\n intended the note to be deleted.\n\n Impact\n\n Exposure of soft-deleted note metadata (title, slug, timestamps) of public books to unauthenticated actors. The note body is not exposed — the\n content endpoint (GetNoteContent) does not use Unscoped(), so its count query returns 0 for soft-deleted notes and yields 404. Impact is therefore\n limited to metadata disclosure and the bypass of the intended \"delete\" semantics on public books.\n\n Remediation\n\n Restrict trash (soft-deleted) listings to the book owner only — never honor the is_public branch when deleted=true:\n\n func (s NotesService) GetNotesByBookID(currentUserID *uuid.UUID, bookID uuid.UUID, deleted bool) ([]db.Note, error) {\n tx := db.DB\n if deleted {\n tx = tx.Unscoped()\n }\n + // Soft-deleted (\"trash\") notes must only ever be listed to the book owner.\n + authz := db.DB.Where(\"owner_id = ? OR is_public = ?\", currentUserID, true)\n + if deleted {\n + authz = db.DB.Where(\"owner_id = ?\", currentUserID)\n + }\n tx = tx.\n Preload(\"Book\").\n Joins(\"JOIN books ON books.id = notes.book_id\").\n Where(\n db.DB.Where(\"books.id = ?\", bookID),\n - db.DB.Where(\"owner_id = ? OR is_public = ?\", currentUserID, true),\n + authz,\n )\n if deleted {\n tx = tx.Where(\"notes.deleted_at IS NOT NULL\")\n }\n var notes []db.Note\n return notes, dbErrorToServiceError(tx.Find(¬es).Error)\n }\n\n With this change, when currentUserID is nil (unauthenticated) and deleted=true, the clause becomes owner_id = NULL, which matches nothing — so\n trash is never exposed to anonymous callers.\n\n Coordinated disclosure / CVE request\n\n We have reported this privately and are happy to assist with any further validation or testing you need. If you agree this qualifies as a security\n vulnerability, we would be grateful if you could request a CVE ID for it — GitHub lets maintainers request a CVE directly from this advisory page\n once it is accepted. Thank you for your time and for maintaining note-mark.\n\n References\n\n - CWE-200: Exposure of Sensitive Information to an Unauthorized Actor\n - CWE-285: Improper Authorization\n - Prior note-mark authorization fix (CVE-2026-40265) established that read paths must scope by owner_id OR is_public; this report covers the trash\n path that the scope did not fully cover.\n\n ---","published":"2026-09-03T15:26:42.538Z","modified":"2026-10-28T02:30:46.611654284Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"},"epss":{"score":0.00243,"percentile":0.15497,"asOf":"2026-09-11"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/enchant97/note-mark/backend","fixedVersion":"0.0.0-20260601210758-9c9b72740f22"}],"fix":{"url":"https://github.com/enchant97/note-mark/commit/9c9b72740f22a06131a8f64b53bb08e3b05b81a6","label":"enchant97/note-mark@9c9b727"},"references":[{"type":"WEB","url":"https://github.com/enchant97/note-mark/releases/tag/v0.19.5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50554.json"},{"type":"ADVISORY","url":"https://github.com/enchant97/note-mark/security/advisories/GHSA-588f-fvcv-xhvf"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-50554"},{"type":"FIX","url":"https://github.com/enchant97/note-mark/commit/9c9b72740f22a06131a8f64b53bb08e3b05b81a6"},{"type":"PACKAGE","url":"https://github.com/enchant97/note-mark"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:30:46.611654284Z"}}