Memory tools in obsidian-tc overwrite unowned notes on disk
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-863.
Summary
obsidian-tc from 1.0.1 before 1.31.4 is affected. Its memory tools regenerate notes without checking note ownership, so a hand-authored note whose name sanitizes to the same path can have its body overwritten (CWE-863). Database changes also happen before filesystem work, so a failed operation can leave the memory graph inconsistent with the notes on disk. An authorized caller with memory-tool permissions can cause this without intending to.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| The-40-Thieves | obsidian-tc | 1.0.1 to before 1.31.4 | 1.31.4 | Patch available | CNA |
| — | obsidian-tc (npm) | 1.0.1 to before 1.31.4 | 1.31.4 | Patch available | GHSA-r3g7-r4hr-m258 |
- obsidian-tc VendorThe-40-Thieves Affected 1.0.1 to before 1.31.4 Fixed in 1.31.4 Patch available CNA
- obsidian-tc (npm) Vendor— Affected 1.0.1 to before 1.31.4 Fixed in 1.31.4 Patch available GHSA-r3g7-r4hr-m258
Remediation
Upgrade the npm package obsidian-tc to version 1.31.4, which fixes this issue. The sources list no fixed version for The-40-Thieves obsidian-tc.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
- Fix · CNA obsidian-tc (The-40-Thieves) Fixed in 1.31.4
- Fix · GHSA-r3g7-r4hr-m258 obsidian-tc (npm) Fixed in 1.31.4 Advisory →
Timeline
- 2026-10-23 Threatist record created from CVE-2026-115478
- 2026-10-23 Alias added: GHSA-r3g7-r4hr-m258
- 2026-10-23 Fix available: npm/[email protected] · GHSA-r3g7-r4hr-m258
- 2026-10-23 CVSS score added · GHSA-r3g7-r4hr-m258
- 2026-10-23 Weakness changed · GHSA-r3g7-r4hr-m258
- 2026-10-23 7 new references · GHSA-r3g7-r4hr-m258
- 2026-10-24 Priority changed: MEDIUM → LOW
- 2026-10-30 CISA SSVC decision points changed
References
Other 6
- https://github.com/The-40-Thieves/obsidian-tc/security/advisories/GHSA-r3g7-r4hr-m258
- https://github.com/The-40-Thieves/obsidian-tc/pull/978
- https://github.com/The-40-Thieves/obsidian-tc/commit/99f7914ca0fbeed92e7c4d39cc8c3e5830dab133
- https://github.com/The-40-Thieves/obsidian-tc/blob/v1.31.4/CHANGELOG.md
- https://github.com/The-40-Thieves/obsidian-tc/releases/tag/v1.31.4
- https://github.com/The-40-Thieves/obsidian-tc
More The-40-Thieves vulnerabilities
- TI-2026-79945 Declined confirmations in obsidian-tc permit destructive tool calls CVSS 4.0HIGH 7.1
- TI-2026-71222 Authorization bypass in obsidian-tc lets tokens access other vaults CVSS 3.1CRITICAL 9.9
- TI-2026-71220 Missing origin checks in obsidian-tc expose local vault to web pages CVSS 3.1HIGH 8.8
- TI-2026-71221 Default ACL in obsidian-tc exposes Obsidian control-directory secrets CVSS 3.1MEDIUM 6.5
- TI-2026-71748 Symlink path mismatch in obsidian-tc bypasses read ACL restrictions CVSS 3.1MEDIUM 4.7
- TI-2026-71798 Missing read ACL checks in obsidian-tc expose note data CVSS 3.1MEDIUM 4.3
Sources
- CVE-2026-115478 · CVE Program
- CVE-2026-115478 · NVD
- FIRST EPSS
- GHSA-r3g7-r4hr-m258 · GitHub Advisory Database · CC BY 4.0
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