CVE-2021-3988

Name: CVE-2021-3988
Creator: NVD / NIST
Published: 2024-11-15T11:15:06.877+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.36%

Last modified Jun 17, 2026

CVE-2021-3988 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. A Cross-site Scripting (XSS) vulnerability exists in janeczku/calibre-web, specifically in the file `edit_books.js`. The vulnerability occurs when editing book properties, such as uploading a cover or a format. EPSS estimates a 0.36% chance of exploitation in the next 30 days.

Description

A Cross-site Scripting (XSS) vulnerability exists in janeczku/calibre-web, specifically in the file `edit_books.js`. The vulnerability occurs when editing book properties, such as uploading a cover or a format. The affected code directly inserts user input into the DOM without proper sanitization, allowing attackers to execute arbitrary JavaScript code. This can lead to various attacks, including stealing cookies. The issue is present in the code handling the `#btn-upload-cover` change event.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.36%

27.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Janeczku	Calibre-Web	< 0.6.15

References

Timeline

Published: Nov 15, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-3988?

How severe is CVE-2021-3988?

CVE-2021-3988 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3988?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-3988?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST