Vulnerability · Published Oct 23, 2026 · Assigned by GitHub_M
CVE-2026-115478obsidian-tc: Memory-lifecycle tools overwrite unowned notes or partially commit lifecycle changes
High 7.1
In plain English
A high-severity incorrect authorization in obsidian-tc from The-40-Thieves. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | obsidian-tc | 1.31.4 | GHSA-r3g7-r4hr-m258 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| The-40-Thieves | obsidian-tc | >= 1.0.1, < 1.31.4 |
Weakness: CWE-459, CWE-863 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N
References
- https://github.com/The-40-Thieves/obsidian-tc/security/advisories/GHSA-r3g7-r4hr-m258 x_refsource_CONFIRM
- https://github.com/The-40-Thieves/obsidian-tc/pull/978 x_refsource_MISC
- https://github.com/The-40-Thieves/obsidian-tc/commit/99f7914ca0fbeed92e7c4d39cc8c3e5830dab133 x_refsource_MISC
- https://github.com/The-40-Thieves/obsidian-tc/blob/v1.31.4/CHANGELOG.md x_refsource_MISC
- https://github.com/The-40-Thieves/obsidian-tc/releases/tag/v1.31.4 x_refsource_MISC