ProofreadPage improperly sanitizes multiline styles using Sanitizer::checkCSS
Priority MEDIUM 64CWE-79Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00382 32nd percentileScored 2026-11-07
Fix Fixed MediaWiki - ProofreadPage Extension (Wikimedia Foundation): 1.43, 1.44, 1.45
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Wikimedia Foundation | MediaWiki - ProofreadPage Extension | before 1.43 | 1.43, 1.44, 1.45 | Patch available | CNA |
- MediaWiki - ProofreadPage Extension VendorWikimedia Foundation Affected before 1.43 Fixed in 1.43, 1.44, 1.45 Patch available CNA
Remediation
- Fix · CNA MediaWiki - ProofreadPage Extension (Wikimedia Foundation) Fixed in 1.43, 1.44, 1.45
Timeline
- 2026-10-02 Threatist record created from CVE-2026-39838
- 2026-10-03 Alias added: GHSA-9jh3-xqmw-83x6
References
More Wikimedia Foundation vulnerabilities
- TI-2025-11006 The compare API module breaks Extension:Lockdown CVSS 4.0CRITICAL 10.0
- TI-2024-32110 Backticks can allow the usage of not-allowed SQL functions CVSS 4.0HIGH 8.8
- TI-2026-65500 Unauthenticated SQL injection in UserPageViewTracker via filterusers and ignoreusers parameters CVSS 3.1HIGH 7.5
- TI-2026-64588 DataTransfer depends on phpspreadsheet version vulnerable to CVE-2026-59933 (XLS/OLE memory exhaustion) CVSS 3.1HIGH 7.5
- TI-2026-42112 SQLi in Cargo extension via year range filter CVSS 4.0MEDIUM 6.9
- TI-2026-42110 Stored XSS through Cargo's map format CVSS 4.0MEDIUM 6.9
Sources
- CVE-2026-39838 · CVE Program
- CVE-2026-39838 · NVD
- FIRST EPSS
- GHSA-9jh3-xqmw-83x6 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences