Is CVE-2026-40451 actively exploited?

No active exploitation of CVE-2026-40451 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-40451 be exploited remotely?

Yes. CVE-2026-40451 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-40451?

CVE-2026-40451 has a CVSS score of 5.1 (MEDIUM).

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MEDIUM

CVE-2026-40451

CWE-79Published: April 22, 2026· Updated: Apr 22, 2026

5.1

CVSS v3.1

EPSS:0.03%probability of exploitation in 30 daysPercentile:9.1th

Official 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.

NVD Source

Technical Analysis

CVE-2026-40451 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation does not require any privileges, though user interaction (A) is needed, which slightly reduces the risk of mass automated attacks.

From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionA

ScopeX

Impact

Confidentiality

Integrity

Availability

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X