CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:H/A:N
Lifecycle Timeline
3Description
Komga is a media server for comics, mangas, BDs, magazines and eBooks. A Cross-Site Scripting (XSS) vulnerability has been discovered in versions 1.8.0 through 1.21.3 when serving EPUB resources, either directly from the API, or when reading using the epub reader. The vulnerability lets an attacker perform actions on the victim's behalf. When targeting an admin user, this can be combined with controlling a server-side command to achieve arbitrary code execution. For this vulnerability to be exploited, a malicious EPUB file has to be present in a Komga library, and subsequently accessed in the Epub reader by an admin user. Version 1.22.0 contains a patch for the issue.
Analysis
Komga is a media server for comics, mangas, BDs, magazines and eBooks. A Cross-Site Scripting (XSS) vulnerability has been discovered in versions 1.8.0 through 1.21.3 when serving EPUB resources, either directly from the API, or when reading using the epub reader. The vulnerability lets an attacker perform actions on the victim's behalf. When targeting an admin user, this can be combined with controlling a server-side command to achieve arbitrary code execution. For this vulnerability to be exploited, a malicious EPUB file has to be present in a Komga library, and subsequently accessed in the Epub reader by an admin user. Version 1.22.0 contains a patch for the issue.
Technical Context
Cross-site scripting (XSS) allows injection of client-side scripts into web pages viewed by other users due to insufficient output encoding. This vulnerability is classified as Improper Control of Interaction Frequency (CWE-799).
Remediation
Encode all user-supplied output contextually (HTML, JS, URL). Implement Content Security Policy (CSP) headers. Use HTTPOnly and Secure cookie flags.
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External POC / Exploit Code
Leaving vuln.today
EUVD-2025-19058