---
id: "CVE-2026-90800"
kind: "vulnerability"
aliases: ["CVE-2026-90800"]
title: "CouchDB: missing auth checks let any request read prefixed _user databases"
severity: "high"
cvss: 8.1
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["couchdb", "package", "self-hosted"]
not_affected_if: ["default-config"]
published_at: "2026-10-20T16:17:16+00:00"
first_seen_at: "2026-10-23T21:57:20+00:00"
updated_at: "2026-10-25T03:06:33+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90800", "first_seen_at": "2026-10-23T21:57:20+00:00"}]
---

# CouchDB: missing auth checks let any request read prefixed _user databases

Apache CouchDB 3.5.2 and earlier lack authorisation checks in its chttpd HTTP layer. A request to an unauthorised API endpoint can read the full contents of a prefixed _users or _replicator database.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the running version with `curl http://localhost:5984/` and look at the `version` field.
- Check whether any prefixed system databases exist, for example by listing all databases with `curl http://localhost:5984/_all_dbs` and looking for names ending in `_users` or `_replicator`.

## Fix

- Upgrade Apache CouchDB to `3.5.3`.

## Timeline

- 2026-10-23T21:57:20+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-90800

## From the sources

Missing authorisation checks in chttpd in Apache CouchDB 3.5.2 and below on all platforms allows any request to read the full contents of a prefixed _user or _replicator database via an unauthorised API endpoint.


The use of prefixed system databases is very rare.

Users are recommended to upgrade to version 3.5.3, which fixes this issue.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_