Security readout for executives and security teams
Plain-English summary
CVE-2026-0671 is a stored cross-site scripting issue in Wikimedia’s MediaWiki UploadWizard extension. A successful attack could cause a user’s browser to run attacker-controlled script after user interaction. The expected impact is limited data exposure or page manipulation, not server takeover. Treat it as a moderate web application risk for affected wiki installations.
Executive priority
Prioritize remediation in the normal security patch cycle, faster for public wikis or environments with sensitive users. This is not presented as actively exploited, but stored XSS can undermine user trust and session integrity.
Technical view
The issue is CWE-79 improper output neutralization in UploadWizard i18n/message-key handling. Affected versions listed are 1.45, 1.44, 1.43, and 1.39. CVSS 3.1 is 6.1: network reachable, low complexity, no privileges required, user interaction required, changed scope, low confidentiality and integrity impact, no availability impact.
Likely exposure
Exposure is limited to MediaWiki deployments using the UploadWizard extension in the listed affected versions. Sites not running UploadWizard, or not on the affected version lines, are not identified as affected in the provided sources.
Exploitation context
The CVE is not listed in KEV, and the provided sources do not state active exploitation. Exploitation requires user interaction, consistent with a stored XSS scenario where a user views affected generated content.
Researcher notes
Public evidence is concise. The CVE identifies multiple stored i18n/message-key XSS issues but does not provide detailed exploit mechanics in the supplied bundle. Use the Wikimedia Phabricator and Gerrit references for authoritative implementation details without assuming additional affected products.
Mitigation direction
- Inventory MediaWiki installations using the UploadWizard extension.
- Identify whether UploadWizard is on version 1.45, 1.44, 1.43, or 1.39.
- Follow Wikimedia guidance in the Phabricator task and Gerrit change references.
- Apply vendor-provided UploadWizard updates or backports when available.
- Consider disabling UploadWizard temporarily if exposure is high and no fix is available.
Validation and detection
- Confirm installed MediaWiki and UploadWizard versions from administrative records or package metadata.
- Check whether local branches include the referenced Wikimedia Gerrit fix.
- Review Wikimedia Phabricator T407157 for status and remediation notes.
- After updating, verify UploadWizard remains functional and affected versions are no longer deployed.
- Monitor security logs for unusual UploadWizard-related content changes or message customizations.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-0671 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N2.82.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://phabricator.wikimedia.org/T407157CVE reference
- https://gerrit.wikimedia.org/r/q/I16de2211594ea9a686868ad7789f9879bf981fa1CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.