---
id: "CVE-2022-0766"
kind: "vulnerability"
aliases: ["CVE-2022-0766", "GHSA-2647-c639-qv2j"]
title: "Server-Side Request Forgery in calibreweb"
severity: "critical"
cvss: 9.8
epss: 0.01315
exploited: false
status: "open"
category: "package"
products: [{"name": "calibreweb", "fixed": ["0.6.17"], "affected": "< 0.6.17", "ecosystem": "pypi"}, {"name": "janeczku calibre-web", "fixed": ["0.6.17"], "affected": "< 0.6.17", "ecosystem": "vendor"}]
ecosystems: ["pypi", "vendor"]
tags: ["calibreweb", "cwe-918", "package", "python", "self-hosted"]
not_affected_if: ["version-0.6.17-or-later"]
published_at: "2022-03-07T07:15:07+00:00"
first_seen_at: "2026-10-27T15:13:25+00:00"
updated_at: "2026-10-27T15:32:59+00:00"
sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-2647-c639-qv2j", "first_seen_at": "2026-10-27T15:13:25+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-0766", "first_seen_at": "2026-10-27T15:32:59+00:00"}]
---

# Server-Side Request Forgery in calibreweb

calibreweb before 0.6.17 has an incomplete fix for an earlier SSRF bug: its blocklist does not catch 0.0.0.0, which resolves to localhost. An attacker can make the server send requests to internal services on its own machine.

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

## Affected

- pypi:calibreweb affected < 0.6.17 fixed 0.6.17
- vendor:janeczku calibre-web affected < 0.6.17 fixed 0.6.17

## How to check

- Run `pip show calibreweb` and compare the version with `0.6.17`
- Check whether the instance can be reached by users who are not trusted, since the flaw is exploited through application features that fetch URLs

## Fix

- Upgrade `calibreweb` to `0.6.17` or later
- Until upgraded, block outbound requests from the server to `0.0.0.0` and localhost at the network level

## Timeline

- 2026-10-27T15:13:25+00:00 ghsa https://github.com/advisories/GHSA-2647-c639-qv2j
- 2026-10-27T15:32:59+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2022-0766

## From the sources

calibreweb prior to version 0.6.17 is vulnerable to server-side request forgery (SSRF). This is due to an incomplete fix for [CVE-2022-0339](https://github.com/advisories/GHSA-4w8p-x6g8-fv64). The blacklist does not check for `0.0.0.0`, which would result in a payload of `0.0.0.0` resolving to `localhost`.

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