Kozou: Unauthenticated MCP HTTP server and bundled dev-stack hardening (DNS-rebinding, request-body limits, read-only reads, default network exposure)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.4 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:H/SC:N/SI:N/SA:N · score source

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Kozou compiles a PostgreSQL schema into an Admin UI, a REST API, and an MCP server. Several hardening gaps in the bundled HTTP surfaces and the scaffolded dev stack are fixed in 1.8.1. Issues 1. MCP HTTP server lacked DNS-rebinding protection. The Streamable HTTP transport is unauthenticated and loopback by default. Without Host/Origin validation, a malicious web page in the operator's browser could rebind a hostname it controls to the loopback address and drive the MCP endpoint — reading schema metadata, or (when the opt-in call execution tool is enabled) executing exposed functions as the execution role. 2. Unbounded request-body buffering (DoS). Both the MCP HTTP server and the in-house REST server read the entire request body into memory with no size limit, so a reachable client could drive the process toward memory exhaustion. 3. Read requests ran in a read/write transaction. The shared role-transaction envelope opened every request with a plain BEGIN, so a GET ran read/write. A…

Published by the source

19 Jun 2026, 20:47 UTC

Last modified by the source

10 Sep 2026, 03:50 UTC

Source last checked

26 Oct 2026, 12:56 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-v52w-28xh-v562

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-v52w-28xh-v562

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# Patch Next advisory brief: GHSA-v52w-28xh-v562

Advisory: Kozou: Unauthenticated MCP HTTP server and bundled dev-stack hardening (DNS-rebinding, request-body limits, read-only reads, default network exposure)
IDs: GHSA-v52w-28xh-v562
Record: https://patchnext.com/advisories/ghsa-v52w-28xh-v562 (revision 3, source checked 26 Oct 2026, 12:56 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @kozou/core 1.8.1; kozou 1.8.1; @kozou/api 1.8.1; @kozou/mcp 1.8.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @kozou/core: affected <= 1.8.0; fixed in 1.8.1
- npm kozou: affected <= 1.8.0; fixed in 1.8.1
- npm @kozou/api: affected <= 1.8.0; fixed in 1.8.1
- npm @kozou/mcp: affected <= 1.8.0; fixed in 1.8.1

## Suggested inspection (read-only)
- `npm ls @kozou/core --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls kozou --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @kozou/api --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @kozou/mcp --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @kozou/core, kozou, @kozou/api, @kozou/mcp.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-v52w-28xh-v562 (OSV record GHSA-v52w-28xh-v562 lists affected ranges: npm kozou >=0 =0 =0 =0 <1.8.1 (fixed))
- Verified: https://github.com/advisories/GHSA-v52w-28xh-v562 (GitHub-reviewed advisory GHSA-v52w-28xh-v562 lists affected ranges: npm kozou >=0 =0 =0 =0 <=1.8.0)

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