Wikimedia Foundation MediaWiki 1.43/1.45/1.46 Wikbase cross site scripting

CVSS Meta Temp Score
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CTI Interest Score
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4.3$0-$5k0.30

Summaryinfo

A vulnerability was found in Wikimedia Foundation MediaWiki 1.43/1.45/1.46. It has been rated as problematic. Affected by this vulnerability is an unknown functionality of the component Wikbase. Performing a manipulation results in cross site scripting. This vulnerability is known as CVE-2026-103439. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability classified as problematic has been found in Wikimedia Foundation MediaWiki 1.43/1.45/1.46. This affects an unknown function of the component Wikbase. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as 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. This is going to have an impact on integrity. The summary by CVE is:

Improper neutralization of Script-Related HTML tags in a web page (basic XSS) vulnerability in The Wikimedia Foundation MediaWiki Wikbase extension allows Cross-Site Scripting (XSS). This issue affects MediaWiki Wikbase extension: 1.46, 1.45, and 1.43.

It is possible to read the advisory at phabricator.wikimedia.org. This vulnerability is uniquely identified as CVE-2026-103439 since 09/30/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1059.007 according to MITRE ATT&CK.

It is declared as proof-of-concept.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

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: 4.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.3
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: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Proof-of-Concept
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

09/30/2026 Advisory disclosed
09/30/2026 +0 days CVE reserved
09/30/2026 +0 days VulDB entry created
09/30/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: phabricator.wikimedia.org
Status: Not defined

CVE: CVE-2026-103439 (🔒)
GCVE (CVE): GCVE-0-2026-103439
GCVE (VulDB): GCVE-100-412335

Entryinfo

Created: 09/30/2026 20:03
Changes: 09/30/2026 20:03 (72)
Complete: 🔍
Cache ID: 216::103

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