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Memory tools in obsidian-tc overwrite unowned notes on disk

Priority LOW 31CWE-459Published · Updated

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

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00323 25th percentileScored 2026-11-07
Fix Fixed obsidian-tc (The-40-Thieves): 1.31.4obsidian-tc (npm): 1.31.4

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

VendorProductAffected versionsFixed inStatusSource
The-40-Thievesobsidian-tc1.0.1 to before 1.31.41.31.4Patch availableCNA
—obsidian-tc (npm)1.0.1 to before 1.31.41.31.4Patch availableGHSA-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

  1. 2026-10-23 Threatist record created from CVE-2026-115478
  2. 2026-10-23 Alias added: GHSA-r3g7-r4hr-m258
  3. 2026-10-23 Fix available: npm/[email protected] · GHSA-r3g7-r4hr-m258
  4. 2026-10-23 CVSS score added · GHSA-r3g7-r4hr-m258
  5. 2026-10-23 Weakness changed · GHSA-r3g7-r4hr-m258
  6. 2026-10-23 7 new references · GHSA-r3g7-r4hr-m258
  7. 2026-10-24 Priority changed: MEDIUM → LOW
  8. 2026-10-30 CISA SSVC decision points changed

References

  • 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