Is CVE-2026-39933 actively exploited?

No active exploitation of CVE-2026-39933 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-39933 be exploited remotely?

Yes. CVE-2026-39933 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-39933?

CVE-2026-39933 has a CVSS score of 6.9 (MEDIUM).

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MEDIUM

CVE-2026-39933

CWE-79Published: April 7, 2026· Updated: Apr 8, 2026

6.9

CVSS v3.1

EPSS:0.05%probability of exploitation in 30 daysPercentile:14.6th

Official Description

Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in The Wikimedia Foundation Mediawiki - GlobalWatchlist Extension allows Cross-Site Scripting (XSS). The issue has been remediated on the `master` branch, and in the release branches for MediaWiki versions 1.43, 1.44, and 1.45.

NVD Source

Technical Analysis

CVE-2026-39933 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

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 InteractionNone

ScopeX

Impact

Confidentiality

Integrity

Availability

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/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