---
id: "CVE-2026-123201"
kind: "vulnerability"
aliases: ["CVE-2026-123201"]
title: "Buku bukuserver: unauthenticated request forgery lets remote users read internal services"
severity: "medium"
cvss: 6.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["buku", "bukuserver", "package", "python", "self-hosted"]
not_affected_if: ["bukuserver-not-running", "cli-only-use"]
published_at: "2026-11-05T19:17:19+00:00"
first_seen_at: "2026-11-05T19:40:36+00:00"
updated_at: "2026-11-05T19:43:31+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123201", "first_seen_at": "2026-11-05T19:40:36+00:00"}]
exploit_sources: []
---

# Buku bukuserver: unauthenticated request forgery lets remote users read internal services

Buku's bukuserver web interface lets an unauthenticated remote attacker make the server request internal hosts through the url parameter of /api/fetch_data or /api/network_handle. The attacker can read the page titles, descriptions and keywords of loopback, private and cloud metadata addresses.

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

## How to check

- Check whether bukuserver is running and reachable from the network, for example with `buku --version` on the host where it is installed.
- Confirm the installed version against the range stated in the sources: through `5.1.1`.

## Fix

- Buku (bukuserver): a patch is linked in the sources, but no fixed version is stated; unknown.

## Timeline

- 2026-11-05T19:40:36+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123201

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/buku-through-5.1.1-ssrf-via-bukuserver-fetch-data-and-network-handle-api
- [fix] Patch: github.com https://github.com/jarun/buku/commit/13f6497afc974f02f1069b760772abe8815d1675

## From the sources

Buku (bukuserver) through 5.1.1 contains an unauthenticated server-side request forgery vulnerability that allows remote attackers to make the server request internal hosts by supplying a url parameter to /api/fetch_data or /api/network_handle. Attackers can target loopback, private, or cloud metadata IP addresses, which pass the weak is_bad_url() check and follow redirects, to discover internal services and read their page titles, descriptions, and keywords.

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