Security advisory
An issue was discovered in MediaWiki before 1.31.10 and 1.32.x through 1.34.x before 1.34.4. The non-jqueryMsg version of mw.message().parse() doesn't escape HTML. This affects both message contents (which are generally safe) and the parameters (which can be based on user input). (When jqueryMsg is loaded, it correctly accepts only whitelisted tags in message contents, and escapes all parameters. Situations with an unloaded jqueryMsg are rare in practice, but can for example occur for Special:SpecialPages on a wiki with no extensions installed.)
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-25828
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 08:19 UTC · Revision 1
Source evidence
An issue was discovered in MediaWiki before 1.31.10 and 1.32.x through 1.34.x before 1.34.4. The non-jqueryMsg version of mw.message().parse() doesn't escape HTML. This affects both message contents (which are generally safe) and the parameters (which can be based on user input). (When jqueryMsg is loaded, it correctly accepts only whitelisted tags in message contents, and escapes all parameters. Situations with an unloaded jqueryMsg are rare in practice, but can for example occur for Special:SpecialPages on a wiki with no extensions installed.)
osv:CVE-2020-25828
Complete source record
{
"id": "fb603c958507ee6fdaf980442b852f767f1ab7b5a2bda297288b14fc58ab5903",
"url": "https://osv.dev/vulnerability/CVE-2020-25828",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-25828",
"summary": "An issue was discovered in MediaWiki before 1.31.10 and 1.32.x through 1.34.x before 1.34.4. The non-jqueryMsg version of mw.message().parse() doesn't escape HTML. This affects both message contents (which are generally safe) and the parameters (which can be based on user input). (When jqueryMsg is loaded, it correctly accepts only whitelisted tags in message contents, and escapes all parameters. Situations with an unloaded jqueryMsg are rare in practice, but can for example occur for Special:SpecialPages on a wiki with no extensions installed.)",
"evidence": "osv:CVE-2020-25828",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2020-25828",
"aliases": [
"BIT-mediawiki-2020-25828",
"CVE-2020-25828",
"GHSA-h8qx-mj6v-2934"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/wikimedia/mediawiki",
"type": "GIT",
"events": [
{
"introduced": "0fbb878ef366477535a709b0c2564bdcf4b176d1"
},
{
"fixed": "e34e7f20b51ed7514ba6de8d8a390363ade2237f"
},
{
"introduced": "0fa7240e6a81be24dc0eb3c250ec2a25a2099faa"
},
{
"last_affected": "0fa7240e6a81be24dc0eb3c250ec2a25a2099faa"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "1.32.0"
},
{
"fixed": "1.34.4"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:mediawiki:mediawiki:1.31.10:*:*:*:*:*:*:*",
"range": [
{
"introduced": "1.31.10"
},
{
"last_affected": "1.31.10"
}
],
"source": "CPE_STRING"
}
]
}
}
],
"versions": [
"1.31.10"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-25828.json"
}
}
],
"modified": "2026-10-24T10:31:05.929482943Z",
"provider": "osv",
"references": [
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RTTPZ7XMDS66I442OLLHXBDNP2LCBJU6/",
"https://lists.wikimedia.org/pipermail/mediawiki-announce",
"https://lists.wikimedia.org/pipermail/mediawiki-l/2020-September/048480.html",
"https://lists.wikimedia.org/pipermail/mediawiki-l/2020-September/048488.html"
],
"provider_metadata": {
"unresolved_ranges": [
{
"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-2020-25828",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 440874,
"published_at": "2020-09-27T21:15:12.877+00:00"
}