CVE-2026-39840 | Wikimedia Cargo Extension up to 3.8.6 on Mediawiki cross site scripting (EUVD-2026-19929)

VDB-355951 · CVE-2026-39840 · EUVD-2026-19929 WIKIMEDIA CARGO EXTENSION UP TO 3.8.6 ON MEDIAWIKI CROSS SITE SCRIPTING HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 3.4 $0-$5k 2.54 Summaryinfo A vulnerability, which was classified as problematic, has been found in Wikimedia Cargo Extension up to 3.8.6 on Mediawiki. This affects an unknown part. This manipulation causes cross site scripting. This vulnerability is handled as CVE-2026-39840. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component. Detailsinfo A vulnerability classified as problematic was found in Wikimedia Cargo Extension up to 3.8.6 on Mediawiki. Affected by this vulnerability is an unknown functionality. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect integrity. The summary by CVE is: Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Wikimedia Foundation Mediawiki - Cargo Extension allows XSS Targeting Non-Script Elements.This issue affects Mediawiki - Cargo Extension: before 3.8.7. The weakness was released by SomeRandomDeveloper. It is possible to read the advisory at phabricator.wikimedia.org. This vulnerability is known as CVE-2026-39840 since 04/07/2026. The exploitation appears to be easy. The attack can be launched remotely. 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. Upgrading to version 3.8.7 eliminates this vulnerability. The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-19929). Productinfo Type Content Management System Vendor Wikimedia Name Cargo Extension Version 3.8.0 3.8.1 3.8.2 3.8.3 3.8.4 3.8.5 3.8.6 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: 3.5 VulDB Meta Temp Score: 3.4 VulDB Base Score: 3.5 VulDB Temp Score: 3.4 VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock 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 Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: Cargo Extension 3.8.7 Timelineinfo 04/07/2026 Advisory disclosed 04/07/2026 +0 days CVE reserved 04/07/2026 +0 days VulDB entry created 04/07/2026 +0 days VulDB entry last update Sourcesinfo Advisory: phabricator.wikimedia.org Researcher: SomeRandomDeveloper Status: Confirmed CVE: CVE-2026-39840 (🔒) GCVE (CVE): GCVE-0-2026-39840 GCVE (VulDB): GCVE-100-355951 EUVD: 🔒 Entryinfo Created: 04/07/2026 23:33 Updated: 04/07/2026 23:45 Changes: 04/07/2026 23:33 (69), 04/07/2026 23:45 (1) Complete: 🔍 Cache ID: 99:6B1:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸