CVE-2026-115478

obsidian-tc: Memory-lifecycle tools overwrite unowned notes or partially commit lifecycle changes

obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian vaults. From 1.0.1 until 1.31.4, `create_entity`, `link_entities`, `rename_entity`, `unlink_entities` and `delete_entity` regenerate memory notes from SQLite at the computed `memory/<type>/<name>.md` path without reliably preserving note ownership or the consistency of a failed lifecycle operation. During shared materialization, a hand-authored note or an orphan left by a different entity whose name sanitized to the same path could have its entire body overwritten on the next write naming that type and name, with non-owned frontmatter preserved. `rename_entity` also seeded the destination path with a direct atomic write without validating ownership and could overwrite a foreign note there. Separately, several tools mutated SQLite before fallible filesystem work: `create_entity` and `link_entities` inserted the row or relation before materialization; `rename_entity` updated the entity, including a retired status, before updating its note; `unlink_entities` removed a relation before rematerializing the source note; and `delete_entity`'s cascade removed the target and its relations before rematerializing neighbouring notes. A later filesystem failure could therefore leave a row or relation changed and the memory graph inconsistent with the notes on disk even when the operation failed. An authorized caller with the required memory-tool permissions could, without intending to, destroy the body of a vault note outside the entity being written; `delete_entity` additionally requires its deletion permission and destructive confirmation, which this memory flaw does not bypass. Snapshots-before-write through `restore_note` mitigate the overwrite only where snapshots are enabled and the note had previously been written through obsidian-tc. This issue is fixed in version 1.31.4.