An issue was discovered in MediaWiki before 1.35.1. Missing users (accounts that don't exist) and hidden users (accounts that have been explicitly hidden due to being abusive, or similar) that the viewer cannot see are handled differently, exposing sensitive information about the hidden status to unprivileged viewers. This exists on various code paths.
CVSS v4.0 Metrics
Exploitability
Attack VectorNetwork
ComplexityLow
RequirementsPresent
PrivilegesNone
User InteractionNone
Threat
Exploit MaturityUnreported
Vulnerable System
ConfidentialityLow
IntegrityNone
AvailabilityNone
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | nvd | AV: P→N, AC: H→L, PR: H→N, UI: A→N, VC: N→L | 0.0 → 1.7 |
| 2026-07-21 | cve.org | initial, patch: Unavailable | 0.0 |
Affected Software
| Vendor | Product | Version |
|---|
| debian | debian_linux | 10.0 |
| debian | debian_linux | 9.0 |
| fedoraproject | fedora | 33 |
| mediawiki | mediawiki | ≤ 1.35.1 |
Published: 2020-12-18
