CVE-2026-77363 obsidian-tc Streamable HTTP transport permits cross-origin loopback vault access
A malicious web page can access local Obsidian vaults via the MCP server's HTTP transport when authentication is disabled, bypassing origin checks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-77363?
CVE-2026-77363 is a high-severity server-side request forgery vulnerability in The-40-Thieves obsidian-tc, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2026-77363?
2 open source packages ship an affected version, including obsidian-tc.
| Package | Affected | Fixed in |
|---|---|---|
obsidian-tc npm | All versions | 1.3.1 |
obsidian-tc npm | All versions | 1.3.1 |
How do I fix CVE-2026-77363?
Upgrade obsidian-tc to 1.3.1 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-77363 being exploited?
There is no known exploitation of CVE-2026-77363 in the wild and no public exploit code.
Sources
Also known as GHSA-pqh8-4pj7-32xx.