Medium
Security advisory
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-35480
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 07:32 UTC · Revision 1
Source evidence
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.
osv:CVE-2020-35480
Complete source record
{
"id": "517befc01f507086ecaa6de3fdf65d3ab385531e65ebc91bcaf671d05535a067",
"url": "https://osv.dev/vulnerability/CVE-2020-35480",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-35480",
"summary": "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.",
"evidence": "osv:CVE-2020-35480",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2020-35480",
"aliases": [
"BIT-mediawiki-2020-35480",
"CVE-2020-35480"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/wikimedia/mediawiki",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "3e26b5ff1468f98cf306575d125b29a6645bf2ea"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "1.35.1"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"1.35.0",
"1.35.0-rc.3",
"1.35.0-rc.2",
"1.35.0-rc.1",
"1.35.0-rc.0",
"test-hashar-for-ci",
"1.6.0",
"1.5.0beta4",
"1.5.0beta3",
"1.5.0beta2",
"1.5.0beta1",
"1.5.0alpha2",
"1.5.0alpha1",
"1.3.0beta1",
"1.1.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-35480.json"
}
}
],
"modified": "2026-10-24T10:30:54.695249615Z",
"provider": "osv",
"references": [
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/STT5Z4A3BCXVH3WIPICWU2FP4IPIMUPC/",
"https://lists.debian.org/debian-lts-announce/2020/12/msg00034.html",
"https://lists.wikimedia.org/pipermail/mediawiki-announce/2020-December/000268.html",
"https://www.debian.org/security/2020/dsa-4816",
"https://phabricator.wikimedia.org/T120883"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
"cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*"
],
"vendor_product": "debian:debian_linux",
"extracted_events": [
{
"range": [
{
"introduced": "9.0"
},
{
"last_affected": "9.0"
},
{
"introduced": "10.0"
},
{
"last_affected": "10.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"range": [
{
"introduced": "33"
},
{
"last_affected": "33"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2020-35480",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 438257,
"published_at": "2020-12-18T08:15:15.437+00:00"
}