Wikimedia ProofreadPage Extension up to 1.43.6/1.44.3/1.45.1 on MediaWiki cross site scripting

CVSS Meta Temp Score
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CTI Interest Score
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4.1$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic was found in Wikimedia ProofreadPage Extension up to 1.43.6/1.44.3/1.45.1 on MediaWiki. This issue affects some unknown processing. Such manipulation leads to cross site scripting. This vulnerability is traded as CVE-2026-39838. The attack may be launched remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Wikimedia ProofreadPage Extension up to 1.43.6/1.44.3/1.45.1 on MediaWiki and classified as problematic. Affected by this issue is an unknown function. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. CVE summarizes:

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

The weakness was shared by SomeRandomDeveloper. The advisory is shared for download at phabricator.wikimedia.org. This vulnerability is handled as CVE-2026-39838 since 04/07/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 1.43.7, 1.44.4 or 1.45.2 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.1

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: ProofreadPage Extension 1.43.7/1.44.4/1.45.2

Timelineinfo

04/07/2026 Advisory disclosed
04/07/2026 +0 days CVE reserved
04/07/2026 +0 days VulDB entry created
07/22/2026 +106 days VulDB entry last update

Sourcesinfo

Advisory: phabricator.wikimedia.org
Researcher: SomeRandomDeveloper
Status: Confirmed

CVE: CVE-2026-39838 (🔒)
GCVE (CVE): GCVE-0-2026-39838
GCVE (VulDB): GCVE-100-355964

Entryinfo

Created: 04/07/2026 23:37
Updated: 07/22/2026 11:20
Changes: 04/07/2026 23:37 (69), 07/22/2026 11:20 (2)
Complete: 🔍
Cache ID: 216::103

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