GitHub Advisoryadvisory · npm
GHSA-r3g7-r4hr-m258 obsidian-tc: Memory-lifecycle tools overwrite unowned notes or partially commit lifecycle changes
HIGH
Official page ↗
- Aliases
- CVE-2026-115478
- Ecosystem
- npm
- Packages
- obsidian-tc
- Severity
- High
- CVSS 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
- Weaknesses
- CWE-459, CWE-863
- Reviewed
- 2026-10-23
Affected packages
• npm obsidian-tc: >= 1.0.1, < 1.31.4 → fixed in 1.31.4
Description
Summary
`create_entity`, `link_entities`, `rename_entity`, `unlink_entities` and `delete_entity` regenerate a memory note's body from SQLite at the computed `memory//.md` path. When a note already existed at that path and was not owned by the entity being written (a hand-authored note, or an orphan left by a different entity whose name sanitized to the same path), its entire body was overwritten on the next write naming that `(type, name)`, keeping only its frontmatter. Separately, several of these tools inserted or removed their SQLite row before the fallible filesystem step, so a refused note write could leave a relation gone, a retired status committed, or the wrong entity deleted.
Details
• `create_entity` and `link_entities` inserted the SQL row or relation before materialization.
• `rename_entity` seeded the destination path with a direct atomic write that bypassed the ownership check, and for a status-only rename could commit a retired status with the note write refused.
• `unlink_entities` removed the relation row before discovering the source note's rematerialization would be refused.
• `delete_entity`'s cascade could delete the target and its relations before a neighbour's note was found to be foreign.
The overwrite exists in every released version since `materializeEntity` shipped (`git show v1.0.1:packages/server/src/memory/materialize.ts`).
Impact
An authorized caller with memory-write scope (any agent using the M5 memory tools) can, without intending to, destroy the body of a vault note outside the entity it is writing, and can leave the memory graph inconsistent with the notes on disk. Snapshots-before-write (`restore_note`) mitigate the overwrite only where snapshots are enabled and the note had been written through obsidian-tc before.
Patches
Fixed in 1.31.4 at the shared primitive: `materializeEntity` refuses to write over a note whose `obsidian_tc_id` is missing or belongs to another entity; a new `assertNoteOwnership` pre-check runs before any SQLite mutation in the three lifecycle tools, so a refusal is a no-op; `create_entity` and `link_entities` roll back the row they had inserted. Verified by `test/m5-memory-ownership.test.ts`, which covers all five call sites and the rollback.
Workarounds
None that preserve the tools. Disabling the `write:memory` scope for callers prevents the write path entirely.
Credit
Found by the maintainer while building `obsidian-tc memory import` (PR #978); the vulnerability class was independently confirmed by a cross-vendor adversarial review.
References
• PR #978 (fix and test), CHANGELOG `## [1.31.4] ### Security`
• `packages/server/src/memory/materialize.ts`, `packages/server/src/tools/m5/memory-lifecycle-tools.ts`
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Related
Alias · CVE (1)
- CVE-2026-115478 obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian vaults. vulnerability
References
- https://github.com/The-40-Thieves/obsidian-tc/security/advisories/GHSA-r3g7-r4hr-m258 web
- https://nvd.nist.gov/vuln/detail/CVE-2026-115478 advisory
- https://github.com/The-40-Thieves/obsidian-tc/pull/978 web
- https://github.com/The-40-Thieves/obsidian-tc/commit/99f7914ca0fbeed92e7c4d39cc8c3e5830dab133 web
- https://github.com/The-40-Thieves/obsidian-tc package
- https://github.com/The-40-Thieves/obsidian-tc/blob/v1.31.4/CHANGELOG.md web
- https://github.com/The-40-Thieves/obsidian-tc/releases/tag/v1.31.4 web