---
title: "CVE-2026-77363: obsidian-tc HTTP transport lacks Origin/DNS-rebinding protection, enabling drive-by vault access on loopback"
url: https://erroneo.us/security/cve/CVE-2026-77363/
description: "CVE-2026-77363 (obsidian-tc (npm)): obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian vaults. Prior to 1.3.1, the Streamable…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-10-12
date_modified: 2026-10-23
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-77363"
kev: false
cvss: 8.8
epss: 0.00157
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-77363: obsidian-tc HTTP transport lacks Origin/DNS-rebinding protection, enabling drive-by vault access on loopback

**Signal:** Normal patch cycle. No exploitation signal; fix it in your next routine update if you are affected. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.2% , percentile 5: FIRST’s model estimates a 0.2% chance of exploitation activity in the next 30 days, higher than 5% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs a user to click or open something. Phishing makes that realistic, but it is not wormable.
- Only applies if your dependency tree includes obsidian-tc (npm) < 1.3.1, fixed in 1.3.1 . Check your lockfile, including transitive dependencies.

## What it is

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.

## Affected packages

- npm `obsidian-tc` < 1.3.1 → fixed: 1.3.1

## Affected products (CVE record)

- The-40-Thieves obsidian-tc: < 1.3.1

## Severity

- GitHub_M CVSS 3.1: 8.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-23): 0.16% probability of exploitation activity in the next 30 days; percentile 5.

## Sources

- [GitHub Advisory GHSA-pqh8-4pj7-32xx](https://github.com/advisories/GHSA-pqh8-4pj7-32xx)
- [CVE.org record CVE-2026-77363](https://www.cve.org/CVERecord?id=CVE-2026-77363)
- [NVD entry CVE-2026-77363](https://nvd.nist.gov/vuln/detail/CVE-2026-77363)
- [github.com](https://github.com/The-40-Thieves/obsidian-tc/security/advisories/GHSA-pqh8-4pj7-32xx)
- [github.com](https://github.com/The-40-Thieves/obsidian-tc/pull/74)
- [github.com](https://github.com/The-40-Thieves/obsidian-tc/commit/6428bfe6fdfd43aa7b4b369be3aecd6a268fb928)
- [github.com](https://github.com/The-40-Thieves/obsidian-tc/releases/tag/v1.3.1)
- [nvd.nist.gov](https://nvd.nist.gov/vuln/detail/cve-2026-77363)

---
Source page: https://erroneo.us/security/cve/CVE-2026-77363/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt