CVE-2021-4170: PYSEC-2026-620 - calibre-web is vulnerable to Cross-site Scripting

CVE-2021-4170 · Severity: low · CVSS 3.1 · Published 2026-07-02

calibre-web is vulnerable to Cross-site Scripting

Technologies: calibreweb (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2021-4170 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2021-4170 being exploited in the wild.
How severe is CVE-2021-4170?
Low severity, with a CVSS score of 3.1, published 2 July 2026.
Which products and versions are affected?
calibreweb (PyPI) ECOSYSTEM:introduced=0,fixed=0.6.15.
Is there a fix for CVE-2021-4170?
Yes. calibreweb (PyPI): upgrade to 0.6.15 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2021-4170?
Check whether you run calibreweb (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • calibreweb (PyPI): upgrade to 0.6.15 or later
    pip install "calibreweb>=0.6.15"

Affected products

  • calibreweb (PyPI) ECOSYSTEM:introduced=0,fixed=0.6.15

Identifiers

  • CVE-2021-4170
  • GHSA-wrp6-9w7f-3wxg
  • PYSEC-2026-620

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