CVE-2025-65858: A Stored Cross-Site Scripting (XSS) vulnerability in Calibre-Web v0.6.25 allows attackers to inject malicious JavaScript into the 'username'

CVE-2025-65858 · Severity: medium · CVSS 4 · Published 2025-12-02

A Stored Cross-Site Scripting (XSS) vulnerability in Calibre-Web v0.6.25 allows attackers to inject malicious JavaScript into the 'username' field during user creation. The payload is stored unsanitized and later executed when the /ajax/listusers endpoint is accessed.

Technologies: calibreweb (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2025-65858 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2025-65858 being exploited in the wild.
How severe is CVE-2025-65858?
Medium severity, with a CVSS score of 4, published 2 December 2025.
Which products and versions are affected?
calibreweb (PyPI) ECOSYSTEM:introduced=0,last_affected=0.6.25.
Is there a fix for CVE-2025-65858?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2025-65858?
Check whether you run Janeczku Calibre-Web or 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.

Affected products

  • Janeczku Calibre-Web
  • calibreweb (PyPI) ECOSYSTEM:introduced=0,last_affected=0.6.25

Identifiers

  • CVE-2025-65858
  • GHSA-pc5g-j9j7-p4q3
  • PYSEC-2026-1234

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