Cross-Site Scripting (XSS) in DeepL Chrome browser extension
Summary
Cross-site scripting in DeepL Chrome browser extension (CVE-2026-40451). Risk of unauthorized operations or information disclosure.
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-40451 has been found in DeepL Chrome browser extension.
Risk of unauthorized operations or information disclosure. CVSS score: 6.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "DeepL Chrome browser extension CVE-2026-40451" on the vendor's site.
CVE-2026-40451 (DeepL Chrome browser extension) — CWE-79 / CVSS v3 6.1
Attack vector: remote (network-reachable) / unauthenticated
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in DeepL Chrome browser extension.
Check the vendor advisory for the affected versions of DeepL Chrome browser extension.
Severity: Medium (CVSS 6.1/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1
Identify exposureidentify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで DeepL Chrome browser extension を使っているサービスとバージョンを洗い出す。
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2
Post-deployment verificationverify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Original description The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD