GHSA-pqh8-4pj7-32xxPublished

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

Collected exploitation and prediction evidence

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

cve-program · CVE-2026-77363

Published

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.

Source published: 12 Oct 2026 17:45:57 UTC
Source modified: 13 Oct 2026 16:03:13 UTC
Observed here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

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CVSS 3.1 · 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

euvd · EUVD-2026-97733

Published

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: Oct 12, 2026, 5:45:57 PM

dateUpdated: Oct 13, 2026, 4:03:13 PM

Source published: Oct 12, 2026, 5:45:57 PM (timezone not stated)
Source modified: Oct 13, 2026, 4:03:13 PM (timezone not stated)
Observed here: 7 Nov 2026 14:29:24 UTC
Source terms: ENISA EUVD · source terms and attribution apply

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EUVD CVSS 3.1 · 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

nvd · CVE-2026-77363

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Deferred

Weakness classifications: CWE-346 · CWE-1385

Original publisher date fields

published: 2026-10-12T18:17:23.513

lastModified: 2026-10-16T20:04:29.760

Source published: 12 Oct 2026 18:17:23 UTC
Source modified: 16 Oct 2026 20:04:29 UTC
Observed here: 25 Oct 2026 16:19:04 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

osv · GHSA-pqh8-4pj7-32xx

Published

### Impact The Streamable HTTP transport was constructed without `enableDnsRebindingProtection`/`allowedHosts`/`allowedOrigins` and performed no `Origin`-header validation. With the documented `auth.mode: "none"` loopback default, a **drive-by web page could `POST http://127.0.0.1/mcp`** and receive caller `http-local` with scopes `["*"]` — full vault read/write — via DNS rebinding / a forged Origin. ### Patches Fixed in **1.3.1**. Upgrade to `>= 1.3.1`. The transport now enables DNS-rebinding protection and allowed hosts/origins and returns HTTP 403 on an invalid Origin (per MCP 2025-11-25). ### Workarounds Do not expose the HTTP transport with `auth.mode: "none"`; require JWT auth, or bind to a non-loopback interface behind a proxy that validates `Origin`.

Source published: 23 Oct 2026 18:29:02 UTC
Source modified: 23 Oct 2026 18:45:08 UTC
Observed here: 24 Oct 2026 13:17:17 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Publisher rating · CRITICAL