What is CVE-2026-40451?

CVE-2026-40451 is a medium-severity vulnerability in Deepl Chrome Browser Extension, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-04-22.

How severe is CVE-2026-40451?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Deepl Chrome Browser Extension

CVE-2026-40451

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…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.000 (11.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Deepl Chrome Browser Extension — versions from v1.22.0 to v.1.23.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

github.com/DeepLcom/deepl-chrome-extension/security/advisories/GHSA-4x2r-q3p9-x…
jvn.jp/en/jp/JVN37524771/

Frequently asked questions

What is CVE-2026-40451?: CVE-2026-40451 is a medium-severity vulnerability in Deepl Chrome Browser Extension, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-04-22.
How severe is CVE-2026-40451?: Medium severity. CVSS v3 base score is 6.1 out of 10.