HighFix available
lxml — security advisory
lxml is a library for processing XML and HTML in the Python language. Prior to 6.1.1, link attributes in ``lxml.html.defs.link_attrs`` were missing ``xlink:href``, which can be used for URL bypass attacks in embedded SVG/MathML/etc. content. This vulnerability was fixed in lxml 6.1.1 and lxml_html_clean 0.4.5.
- Products
- lxml
- Affected versions
- 3.2.0-1, 3.3.0~beta2-1, 3.3.0~beta4-1, 3.3.1-1, 3.3.2-1, 3.3.2-1build1, 3.3.3-1, 3.3.3-1ubuntu0.1, 3.3.3-1ubuntu0.2, 3.3.3-1ubuntu0.2+esm1, 3.3.3-1ubuntu0.2+esm2, 3.3.3-1ubuntu0.2+esm3, 3.3.3-1ubuntu0.2+esm5, 3.4.4-1, 3.5.0-1, 3.5.0-1build1, 3.5.0-1ubuntu0.1, 3.5.0-1ubuntu0.2, 3.5.0-1ubuntu0.3, 3.5.0-1ubuntu0.4, 3.5.0-1ubuntu0.4+esm2, 4.0.0-1, 4.1.0-1, 4.2.0-1, 4.2.1-1, 4.2.1-1ubuntu0.1, 4.2.1-1ubuntu0.2, 4.2.1-1ubuntu0.3, 4.2.1-1ubuntu0.4, 4.2.1-1ubuntu0.6, 4.4.1-1, 4.4.1-1build1, 4.4.2-1, 4.5.0-1, 4.5.0-1ubuntu0.1, 4.5.0-1ubuntu0.2, 4.5.0-1ubuntu0.3, 4.5.0-1ubuntu0.5, 4.6.3+dfsg-0.1, 4.6.4-1, 4.6.4-1ubuntu1, 4.7.1-1, 4.8.0-1, 4.8.0-1build1, 4.9.3-1, 4.9.3-1build1, 4.9.4-1, 5.1.0-1, 5.1.0-1build1, 5.1.0-1build2, 5.2.1-1, 6.0.1-1, 6.0.1-1build1, 6.0.2-1, 6.0.2-1build1
- Fixed versions
- 3.3.3-1ubuntu0.2+esm6, 3.5.0-1ubuntu0.4+esm3, 4.2.1-1ubuntu0.6+esm1, 4.5.0-1ubuntu0.5+esm1, 4.8.0-1ubuntu0.1, 5.2.1-1ubuntu0.2, 6.0.2-1ubuntu0.1
- CVEs
- CVE-2026-49825
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 28 Oct 2026, 10:04 UTC · Revision 1
Source evidence
lxml is a library for processing XML and HTML in the Python language. Prior to 6.1.1, link attributes in ``lxml.html.defs.link_attrs`` were missing ``xlink:href``, which can be used for URL bypass attacks in embedded SVG/MathML/etc. content. This vulnerability was fixed in lxml 6.1.1 and lxml_html_clean 0.4.5.
osv:UBUNTU-CVE-2026-49825
lxml
Fixed versions: 3.3.3-1ubuntu0.2+esm6
lxml
Fixed versions: 3.5.0-1ubuntu0.4+esm3
lxml
Fixed versions: 4.2.1-1ubuntu0.6+esm1
lxml
Fixed versions: 4.5.0-1ubuntu0.5+esm1
lxml
Fixed versions: 4.8.0-1ubuntu0.1
lxml
Fixed versions: 5.2.1-1ubuntu0.2
lxml
Fixed versions: 6.0.2-1ubuntu0.1
Complete source record
{
"id": "cd03c859f62f218ffe2a84f2e652c5e1f1316a395369ecfc122a9a2f29f14209",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-49825",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-49825",
"summary": "lxml is a library for processing XML and HTML in the Python language. Prior to 6.1.1, link attributes in ``lxml.html.defs.link_attrs`` were missing ``xlink:href``, which can be used for URL bypass attacks in embedded SVG/MathML/etc. content. This vulnerability was fixed in lxml 6.1.1 and lxml_html_clean 0.4.5.",
"evidence": "osv:UBUNTU-CVE-2026-49825",
"products": [
{
"name": {
"value": "lxml",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "3.3.3-1ubuntu0.2+esm6",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "3.2.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.0~beta2-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.0~beta4-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.2-1build1",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.3-1ubuntu0.1",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.3-1ubuntu0.2",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.3-1ubuntu0.2+esm1",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.3-1ubuntu0.2+esm2",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.3-1ubuntu0.2+esm3",
"evidence": "/affected/0/versions"
},
{
"value": "3.3.3-1ubuntu0.2+esm5",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "lxml",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "3.5.0-1ubuntu0.4+esm3",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": [
{
"value": "3.4.4-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.0-1build1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.0-1ubuntu0.1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.0-1ubuntu0.2",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.0-1ubuntu0.3",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.0-1ubuntu0.4",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.0-1ubuntu0.4+esm2",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "lxml",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.2.1-1ubuntu0.6+esm1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "4.0.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.1.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.2.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.2.1-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.2.1-1ubuntu0.1",
"evidence": "/affected/2/versions"
},
{
"value": "4.2.1-1ubuntu0.2",
"evidence": "/affected/2/versions"
},
{
"value": "4.2.1-1ubuntu0.3",
"evidence": "/affected/2/versions"
},
{
"value": "4.2.1-1ubuntu0.4",
"evidence": "/affected/2/versions"
},
{
"value": "4.2.1-1ubuntu0.6",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "lxml",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.5.0-1ubuntu0.5+esm1",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": [
{
"value": "4.4.1-1",
"evidence": "/affected/3/versions"
},
{
"value": "4.4.1-1build1",
"evidence": "/affected/3/versions"
},
{
"value": "4.4.2-1",
"evidence": "/affected/3/versions"
},
{
"value": "4.5.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "4.5.0-1ubuntu0.1",
"evidence": "/affected/3/versions"
},
{
"value": "4.5.0-1ubuntu0.2",
"evidence": "/affected/3/versions"
},
{
"value": "4.5.0-1ubuntu0.3",
"evidence": "/affected/3/versions"
},
{
"value": "4.5.0-1ubuntu0.5",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "lxml",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.8.0-1ubuntu0.1",
"evidence": "/affected/4/ranges"
}
],
"affected_versions": [
{
"value": "4.6.3+dfsg-0.1",
"evidence": "/affected/4/versions"
},
{
"value": "4.6.4-1",
"evidence": "/affected/4/versions"
},
{
"value": "4.6.4-1ubuntu1",
"evidence": "/affected/4/versions"
},
{
"value": "4.7.1-1",
"evidence": "/affected/4/versions"
},
{
"value": "4.8.0-1",
"evidence": "/affected/4/versions"
},
{
"value": "4.8.0-1build1",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "lxml",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.2.1-1ubuntu0.2",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": [
{
"value": "4.9.3-1",
"evidence": "/affected/5/versions"
},
{
"value": "4.9.3-1build1",
"evidence": "/affected/5/versions"
},
{
"value": "4.9.4-1",
"evidence": "/affected/5/versions"
},
{
"value": "5.1.0-1",
"evidence": "/affected/5/versions"
},
{
"value": "5.1.0-1build1",
"evidence": "/affected/5/versions"
},
{
"value": "5.1.0-1build2",
"evidence": "/affected/5/versions"
},
{
"value": "5.2.1-1",
"evidence": "/affected/5/versions"
}
]
},
{
"name": {
"value": "lxml",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.0.2-1ubuntu0.1",
"evidence": "/affected/6/ranges"
}
],
"affected_versions": [
{
"value": "6.0.1-1",
"evidence": "/affected/6/versions"
},
{
"value": "6.0.1-1build1",
"evidence": "/affected/6/versions"
},
{
"value": "6.0.2-1",
"evidence": "/affected/6/versions"
},
{
"value": "6.0.2-1build1",
"evidence": "/affected/6/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2026-49825",
"aliases": [
"UBUNTU-CVE-2026-49825"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.3.3-1ubuntu0.2+esm6"
}
]
}
],
"package": {
"name": "lxml",
"purl": "pkg:deb/ubuntu/lxml?arch=source&distro=esm-infra-legacy%2Ftrusty",
"ecosystem": "Ubuntu:Pro:14.04:LTS"
},
"versions": [
"3.2.0-1",
"3.3.0~beta2-1",
"3.3.0~beta4-1",
"3.3.1-1",
"3.3.2-1",
"3.3.2-1build1",
"3.3.3-1",
"3.3.3-1ubuntu0.1",
"3.3.3-1ubuntu0.2",
"3.3.3-1ubuntu0.2+esm1",
"3.3.3-1ubuntu0.2+esm2",
"3.3.3-1ubuntu0.2+esm3",
"3.3.3-1ubuntu0.2+esm5"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49825.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python-lxml",
"binary_version": "3.3.3-1ubuntu0.2+esm6"
},
{
"binary_name": "python3-lxml",
"binary_version": "3.3.3-1ubuntu0.2+esm6"
}
],
"availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.5.0-1ubuntu0.4+esm3"
}
]
}
],
"package": {
"name": "lxml",
"purl": "pkg:deb/ubuntu/lxml?arch=source&distro=esm-infra-legacy%2Fxenial",
"ecosystem": "Ubuntu:Pro:16.04:LTS"
},
"versions": [
"3.4.4-1",
"3.5.0-1",
"3.5.0-1build1",
"3.5.0-1ubuntu0.1",
"3.5.0-1ubuntu0.2",
"3.5.0-1ubuntu0.3",
"3.5.0-1ubuntu0.4",
"3.5.0-1ubuntu0.4+esm2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49825.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python-lxml",
"binary_version": "3.5.0-1ubuntu0.4+esm3"
},
{
"binary_name": "python3-lxml",
"binary_version": "3.5.0-1ubuntu0.4+esm3"
}
],
"availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.2.1-1ubuntu0.6+esm1"
}
]
}
],
"package": {
"name": "lxml",
"purl": "pkg:deb/ubuntu/lxml?arch=source&distro=esm-infra%2Fbionic",
"ecosystem": "Ubuntu:Pro:18.04:LTS"
},
"versions": [
"4.0.0-1",
"4.1.0-1",
"4.2.0-1",
"4.2.1-1",
"4.2.1-1ubuntu0.1",
"4.2.1-1ubuntu0.2",
"4.2.1-1ubuntu0.3",
"4.2.1-1ubuntu0.4",
"4.2.1-1ubuntu0.6"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49825.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python-lxml",
"binary_version": "4.2.1-1ubuntu0.6+esm1"
},
{
"binary_name": "python3-lxml",
"binary_version": "4.2.1-1ubuntu0.6+esm1"
}
],
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.5.0-1ubuntu0.5+esm1"
}
]
}
],
"package": {
"name": "lxml",
"purl": "pkg:deb/ubuntu/lxml?arch=source&distro=esm-infra%2Ffocal",
"ecosystem": "Ubuntu:Pro:20.04:LTS"
},
"versions": [
"4.4.1-1",
"4.4.1-1build1",
"4.4.2-1",
"4.5.0-1",
"4.5.0-1ubuntu0.1",
"4.5.0-1ubuntu0.2",
"4.5.0-1ubuntu0.3",
"4.5.0-1ubuntu0.5"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49825.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python-lxml",
"binary_version": "4.5.0-1ubuntu0.5+esm1"
},
{
"binary_name": "python3-lxml",
"binary_version": "4.5.0-1ubuntu0.5+esm1"
}
],
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.8.0-1ubuntu0.1"
}
]
}
],
"package": {
"name": "lxml",
"purl": "pkg:deb/ubuntu/lxml?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"4.6.3+dfsg-0.1",
"4.6.4-1",
"4.6.4-1ubuntu1",
"4.7.1-1",
"4.8.0-1",
"4.8.0-1build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49825.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python3-lxml",
"binary_version": "4.8.0-1ubuntu0.1"
}
],
"availability": "No subscription required"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.2.1-1ubuntu0.2"
}
]
}
],
"package": {
"name": "lxml",
"purl": "pkg:deb/ubuntu/lxml?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"4.9.3-1",
"4.9.3-1build1",
"4.9.4-1",
"5.1.0-1",
"5.1.0-1build1",
"5.1.0-1build2",
"5.2.1-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49825.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python3-lxml",
"binary_version": "5.2.1-1ubuntu0.2"
}
],
"availability": "No subscription required"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "6.0.2-1ubuntu0.1"
}
]
}
],
"package": {
"name": "lxml",
"purl": "pkg:deb/ubuntu/lxml?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"6.0.1-1",
"6.0.1-1build1",
"6.0.2-1",
"6.0.2-1build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49825.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python3-lxml",
"binary_version": "6.0.2-1ubuntu0.1"
}
],
"availability": "No subscription required"
}
}
],
"modified": "2026-10-08T19:47:12.564846338Z",
"provider": "osv",
"upstream": [
"CVE-2026-49825"
],
"references": [
"https://ubuntu.com/security/CVE-2026-49825",
"https://www.cve.org/CVERecord?id=CVE-2026-49825",
"https://ubuntu.com/security/notices/USN-8897-1"
]
},
"related_cves": [
{
"value": "CVE-2026-49825",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 104550,
"published_at": "2026-08-20T15:17:00+00:00"
}