UnratedFix available
Fix CVE(s): CVE-2026-86138, CVE-2026-86140, CVE-2026-86143, CVE-2026-86144
Type: advisorySources: OSV
* SECURITY UPDATE: integer overflow leading to heap buffer overflow in xmlDictAddQString() - debian/patches/CVE-2026-86138.patch: add SIZE_MAX-based overflow guards to the pool size computation in xmlDictAddQString() in dict.c, plus a SIZE_MAX fallback define, so an oversized prefix and name can no longer wrap the allocation size and let the following memcpy() write past the dictionary string pool - CVE-2026-86138
- Products
- libxml2, libxml2-dev, libxml2-doc, libxml2-utils, python-libxml2, python3-libxml2
- Affected versions
- Not specified
- Fixed versions
- 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14
- CVEs
- CVE-2026-86138, CVE-2026-86140, CVE-2026-86143, CVE-2026-86144
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 11:00 UTC · Revision 1
Source evidence
Fix CVE(s): CVE-2026-86138, CVE-2026-86140, CVE-2026-86143, CVE-2026-86144
core-osv · Original sourcePublished 18 Sept 2026, 08:11 UTC
* SECURITY UPDATE: integer overflow leading to heap buffer overflow in xmlDictAddQString() - debian/patches/CVE-2026-86138.patch: add SIZE_MAX-based overflow guards to the pool size computation in xmlDictAddQString() in dict.c, plus a SIZE_MAX fallback define, so an oversized prefix and name can no longer wrap the allocation size and let the following memcpy() write past the dictionary string pool - CVE-2026-86138
osv:CLSA-2026-1789567256
libxml2
Fixed versions: 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14
libxml2-dev
Fixed versions: 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14
libxml2-doc
Fixed versions: 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14
libxml2-utils
Fixed versions: 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14
python-libxml2
Fixed versions: 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14
python3-libxml2
Fixed versions: 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14
Complete source record
{
"id": "dd2e56894fbf7d9ebafbc743fae6124dd733526d8ff5888a59fe755538e475f2",
"url": "https://osv.dev/vulnerability/CLSA-2026-1789567256",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Fix CVE(s): CVE-2026-86138, CVE-2026-86140, CVE-2026-86143, CVE-2026-86144",
"summary": "* SECURITY UPDATE: integer overflow leading to heap buffer overflow in xmlDictAddQString() - debian/patches/CVE-2026-86138.patch: add SIZE_MAX-based overflow guards to the pool size computation in xmlDictAddQString() in dict.c, plus a SIZE_MAX fallback define, so an oversized prefix and name can no longer wrap the allocation size and let the following memcpy() write past the dictionary string pool - CVE-2026-86138",
"evidence": "osv:CLSA-2026-1789567256",
"products": [
{
"name": {
"value": "libxml2",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "libxml2-dev",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "libxml2-doc",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "libxml2-utils",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "python-libxml2",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14",
"evidence": "/affected/4/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "python3-libxml2",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "CLSA-2026-1789567256",
"aliases": [
"CLSA-2026-1789567256"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14"
}
]
}
],
"package": {
"name": "libxml2",
"purl": "pkg:deb/tuxcare/libxml2?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1789567256.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14"
}
]
}
],
"package": {
"name": "libxml2-dev",
"purl": "pkg:deb/tuxcare/libxml2-dev?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1789567256.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14"
}
]
}
],
"package": {
"name": "libxml2-doc",
"purl": "pkg:deb/tuxcare/libxml2-doc?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1789567256.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14"
}
]
}
],
"package": {
"name": "libxml2-utils",
"purl": "pkg:deb/tuxcare/libxml2-utils?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1789567256.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14"
}
]
}
],
"package": {
"name": "python-libxml2",
"purl": "pkg:deb/tuxcare/python-libxml2?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1789567256.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els14"
}
]
}
],
"package": {
"name": "python3-libxml2",
"purl": "pkg:deb/tuxcare/python3-libxml2?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1789567256.json"
}
}
],
"modified": "2026-10-26T09:31:40.193523840Z",
"provider": "osv",
"upstream": [
"CVE-2026-86138",
"CVE-2026-86140",
"CVE-2026-86143",
"CVE-2026-86144"
],
"references": [
"https://errata.tuxcare.com/els_os/ubuntu20.04els/CLSA-2026-1789567256.html",
"https://nvd.nist.gov/vuln/detail/CVE-2026-86138",
"https://nvd.nist.gov/vuln/detail/CVE-2026-86140",
"https://nvd.nist.gov/vuln/detail/CVE-2026-86143",
"https://nvd.nist.gov/vuln/detail/CVE-2026-86144"
]
},
"related_cves": [
{
"value": "CVE-2026-86138",
"evidence": "/upstream"
},
{
"value": "CVE-2026-86140",
"evidence": "/upstream"
},
{
"value": "CVE-2026-86143",
"evidence": "/upstream"
},
{
"value": "CVE-2026-86144",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 448043,
"published_at": "2026-09-18T08:11:24+00:00"
}