CVE-2026-77363

obsidian-tc Streamable HTTP transport permits cross-origin loopback vault access

CVSS score

8.8

EPSS probability

—

Risk score

0.9

Published

5 h ago

Overview Public Exploits (0)Newsroom Vulnerability Timeline

Patch status has not yet been verified

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Impact on My Inventory

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Vulnerability description

CVE AI research

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DayBreach AI Explanation

Verified against sources

CVE-2026-77363: obsidian-tc Prior to 1.3.1 Cross-Origin Loopback Vault Access Vulnerability

Sources read

Source agreement

Tam uyum

Evidence confidence

%63

Short explanation

In obsidian-tc prior to 1.3.1, the Streamable HTTP transport fails to validate Host or Origin headers and lacks DNS-rebinding protection. When auth.mode is set to none, malicious web pages can send requests to the local MCP endpoint and obtain unrestricted vault access.

Why does it matter?

If authentication modes are left unconfigured, external web pages can exploit local obsidian-tc instances, exposing sensitive vault data and threatening overall system integrity.

What should be done?

Follow vendor advisories and update guidance
Review and harden auth.mode configurations

Chain of evidence and sources2 verified claims

obsidian-tc 1.3.1 öncesi sürümlerde Streamable HTTP aktarımı Host veya Origin başlıklarını doğrulamamaktadır.

S0 · daybreach-canonical S1 · cvelist S2 · nvd

auth.mode ayarı none olarak ayarlandığında kötü amaçlı web sayfaları yerel MCP uç noktasına istek gönderebilmektedir.

S0 · daybreach-canonical S1 · cvelist S2 · nvd

Show the technical text from the sources

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.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CWE: CWE-346, CWE-1385

Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-77363 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

ID	VENDOR	PRODUCT	ACTION
1	The-40-Thieves	obsidian-tc	View

Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCORE	VERSION	SEVERITY	VECTOR	SOURCE
8.8	CVSS V31	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H	NVD
8.8	CVSS V3_1	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H	CVE CNA

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.

Restrict access to internet-facing services and apply network segmentation.

Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.

Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-77363 is associated with the following CWEs:

CWE-346: Common Weakness Enumeration Entry CWE-346 CWE-1385: Common Weakness Enumeration Entry CWE-1385

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-77363 weaknesses.

CAPEC-66: SQL Injection CAPEC-126: Path Traversal CAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden

PermissionsGerekmiyor

UserGerekiyor

Official Sources and Advisories

https://github.com/The-40-Thieves/obsidian-tc/security/advisories/GHSA-pqh8-4pj7-32xxvendor-advisory https://github.com/The-40-Thieves/obsidian-tc/pull/74vendor-advisory https://github.com/The-40-Thieves/obsidian-tc/commit/6428bfe6fdfd43aa7b4b369be3aecd6a268fb928vendor-advisory https://github.com/The-40-Thieves/obsidian-tc/releases/tag/v1.3.1vendor-advisory

CVSS Vector Radar Chart

8.8 / 10

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone required

User Interaction—

Confidentiality (Gizlilik)Low

Integrity (Bütünlük)High

Availability (Erişilebilirlik)High

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Follow the vendor

The-40-Thieves

Weakness Type (CWE & CAPEC)

CWE-346 CWE-1385

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