Cross-Site Scripting in DeepL Chrome Extension Enables Script Injection

Publication date: 2026-04-22

Last updated on: 2026-06-16

Assigner: JPCERT/CC

Description

DeepL Chrome browser extension versions from v1.22.0 to v.1.23.0 contain a cross-site scripting vulnerability, which allows an attacker to execute arbitrary script in a user's browser, and inject malicious HTML into web pages viewed by the user.

CVSS Scores

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Meta Information

Published

2026-04-22

Last Modified

2026-06-16

Generated

2026-07-06

AI Q&A

2026-04-22

EPSS Evaluated

2026-07-05

NVD

CVE-2026-40451

EUVD

EUVD-2026-24605

Affected Vendors & Products

Vendor	Product	Version / Range
deepl	chrome_extension	From 1.22.0 (inc) to 1.23.0 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-79	The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Attack-Flow Graph

Executive Summary

This vulnerability exists in the DeepL Chrome browser extension versions from v1.22.0 to v1.23.0. It is a cross-site scripting (XSS) vulnerability that allows an attacker to execute arbitrary scripts in a user's browser. Additionally, the attacker can inject malicious HTML into web pages viewed by the user.

Impact Analysis

The vulnerability can impact you by allowing attackers to run malicious scripts in your browser without your permission. This can lead to unauthorized actions such as stealing sensitive information, hijacking user sessions, or manipulating the content of web pages you visit.

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