CVE-2021-42044Public exploitNetwork attack vector

Stored XSS via unescaped Mentor dashboard messages

Published Oct 6, 2021 · Updated Aug 4, 2024

Stored XSS in MediaWiki GrowthExperiments through 1.36.2 allows remote authenticated users to execute JavaScript in mentors' browsers. Mentor dashboard code appends five administrator-editable MediaWiki message strings as HTML instead of escaping them as text. A wiki administrator must store the payload, and execution occurs when a mentor opens the dashboard, exposing that mentor's browser session to script-controlled reads and actions.

CVSS severity4.8
Medium
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in MediaWiki GrowthExperiments through 1.36.2 allows remote authenticated users to execute JavaScript in mentors' browsers. Mentor dashboard code appends five administrator-editable MediaWiki message strings as HTML instead of escaping them as text. A wiki administrator must store the payload, and execution occurs when a mentor opens the dashboard, exposing that mentor's browser session to script-controlled reads and actions.

The record

CVE
CVE-2021-42044
Published
Oct 6, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Oct 6, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

3.5NIST National Vulnerability DatabaseAV:N/AC:M/Au:S/C:N/I:P/A:N
4.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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