Fix CVE(s): CVE-2026-6653, CVE-2026-86143, CVE-2026-86144
* SECURITY UPDATE: use-after-free in the DTD parser reachable through parameter-entity references - debian/patches/CVE-2026-6653.patch: drop the post-inputPush XML_PARSER_EOF early return from xmlPushInput() in parser.c. It reported an already-halted parser as a push failure after ownership of the input had been transferred, so xmlParsePEReference() freed the input still installed as ctxt->input and xmlParseInternalSubset() read through the dangling pointer. The flaw is introduced by the CVE-2021-3541 backport, not by the shipped version. - CVE-2026-6653
- 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.els12
- CVEs
- CVE-2021-3541, CVE-2026-6653, CVE-2026-86143, CVE-2026-86144
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 11:45 UTC · Revision 1
Source evidence
Fix CVE(s): CVE-2026-6653, CVE-2026-86143, CVE-2026-86144
core-osv · Original sourcePublished 24 Sept 2026, 07:01 UTC
* SECURITY UPDATE: use-after-free in the DTD parser reachable through parameter-entity references - debian/patches/CVE-2026-6653.patch: drop the post-inputPush XML_PARSER_EOF early return from xmlPushInput() in parser.c. It reported an already-halted parser as a push failure after ownership of the input had been transferred, so xmlParsePEReference() freed the input still installed as ctxt->input and xmlParseInternalSubset() read through the dangling pointer. The flaw is introduced by the CVE-2021-3541 backport, not by the shipped version. - CVE-2026-6653
osv:CLSA-2026-1789202279
libxml2
Fixed versions: 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12
libxml2-dev
Fixed versions: 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12
libxml2-doc
Fixed versions: 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12
libxml2-utils
Fixed versions: 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12
python-libxml2
Fixed versions: 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12
python3-libxml2
Fixed versions: 2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12
Complete source record
{
"id": "fc2926e12eb1473743107610c7bff2e4b832f7fc9593dea7ae1b11ba1b6f535a",
"url": "https://osv.dev/vulnerability/CLSA-2026-1789202279",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Fix CVE(s): CVE-2026-6653, CVE-2026-86143, CVE-2026-86144",
"summary": "* SECURITY UPDATE: use-after-free in the DTD parser reachable through parameter-entity references - debian/patches/CVE-2026-6653.patch: drop the post-inputPush XML_PARSER_EOF early return from xmlPushInput() in parser.c. It reported an already-halted parser as a push failure after ownership of the input had been transferred, so xmlParsePEReference() freed the input still installed as ctxt->input and xmlParseInternalSubset() read through the dangling pointer. The flaw is introduced by the CVE-2021-3541 backport, not by the shipped version. - CVE-2026-6653",
"evidence": "osv:CLSA-2026-1789202279",
"products": [
{
"name": {
"value": "libxml2",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12",
"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.els12",
"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.els12",
"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.els12",
"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.els12",
"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.els12",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "CLSA-2026-1789202279",
"aliases": [
"CLSA-2026-1789202279"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12"
}
]
}
],
"package": {
"name": "libxml2",
"purl": "pkg:deb/tuxcare/libxml2?distro=debian-10",
"ecosystem": "TuxCare:Debian:10"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/debian10els/CLSA-2026-1789202279.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12"
}
]
}
],
"package": {
"name": "libxml2-dev",
"purl": "pkg:deb/tuxcare/libxml2-dev?distro=debian-10",
"ecosystem": "TuxCare:Debian:10"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/debian10els/CLSA-2026-1789202279.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12"
}
]
}
],
"package": {
"name": "libxml2-doc",
"purl": "pkg:deb/tuxcare/libxml2-doc?distro=debian-10",
"ecosystem": "TuxCare:Debian:10"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/debian10els/CLSA-2026-1789202279.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12"
}
]
}
],
"package": {
"name": "libxml2-utils",
"purl": "pkg:deb/tuxcare/libxml2-utils?distro=debian-10",
"ecosystem": "TuxCare:Debian:10"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/debian10els/CLSA-2026-1789202279.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12"
}
]
}
],
"package": {
"name": "python-libxml2",
"purl": "pkg:deb/tuxcare/python-libxml2?distro=debian-10",
"ecosystem": "TuxCare:Debian:10"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/debian10els/CLSA-2026-1789202279.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.9.10+dfsg-5ubuntu0.20.04.10+tuxcare.els12"
}
]
}
],
"package": {
"name": "python3-libxml2",
"purl": "pkg:deb/tuxcare/python3-libxml2?distro=debian-10",
"ecosystem": "TuxCare:Debian:10"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/debian10els/CLSA-2026-1789202279.json"
}
}
],
"modified": "2026-10-26T09:43:12.482842088Z",
"provider": "osv",
"upstream": [
"CVE-2021-3541",
"CVE-2026-6653",
"CVE-2026-86143",
"CVE-2026-86144"
],
"references": [
"https://errata.tuxcare.com/els_os/debian10els/CLSA-2026-1789202279.html",
"https://nvd.nist.gov/vuln/detail/CVE-2026-6653",
"https://nvd.nist.gov/vuln/detail/CVE-2026-86143",
"https://nvd.nist.gov/vuln/detail/CVE-2026-86144"
]
},
"related_cves": [
{
"value": "CVE-2021-3541",
"evidence": "/upstream"
},
{
"value": "CVE-2026-6653",
"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": 449753,
"published_at": "2026-09-24T07:01:14+00:00"
}