HighFix available
libx11 — security advisory
A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.
- Products
- libx11
- Affected versions
- 2:1.6.1-1ubuntu1, 2:1.6.1-1ubuntu2, 2:1.6.2-1ubuntu1, 2:1.6.2-1ubuntu2, 2:1.6.2-1ubuntu2.1, 2:1.6.2-1ubuntu2.1+esm1, 2:1.6.2-1ubuntu2.1+esm2, 2:1.6.2-1ubuntu2.1+esm3, 2:1.6.2-1ubuntu2.1+esm4, 2:1.6.2-1ubuntu2.1+esm5, 2:1.6.3-1ubuntu2, 2:1.6.3-1ubuntu2.1, 2:1.6.3-1ubuntu2.2, 2:1.6.3-1ubuntu2.2+esm1, 2:1.6.3-1ubuntu2.2+esm2, 2:1.6.3-1ubuntu2.2+esm3, 2:1.6.3-1ubuntu2.2+esm4, 2:1.6.4-3, 2:1.6.4-3ubuntu0.1, 2:1.6.4-3ubuntu0.2, 2:1.6.4-3ubuntu0.3, 2:1.6.4-3ubuntu0.4, 2:1.6.4-3ubuntu0.4+esm1, 2:1.6.4-3ubuntu0.4+esm2, 2:1.6.8-1, 2:1.6.9-2, 2:1.6.9-2ubuntu1, 2:1.6.9-2ubuntu1.1, 2:1.6.9-2ubuntu1.2, 2:1.6.9-2ubuntu1.5, 2:1.6.9-2ubuntu1.6, 2:1.7.2-1, 2:1.7.2-2, 2:1.7.2-2build1, 2:1.7.5-1, 2:1.7.5-1ubuntu0.2, 2:1.7.5-1ubuntu0.3, 2:1.8.12-1build1, 2:1.8.12-1build2, 2:1.8.13-1, 2:1.8.6-1ubuntu1, 2:1.8.7-1, 2:1.8.7-1build1
- Fixed versions
- 2:1.6.2-1ubuntu2.1+esm6, 2:1.6.3-1ubuntu2.2+esm5, 2:1.6.4-3ubuntu0.4+esm3, 2:1.6.9-2ubuntu1.6+esm1, 2:1.7.5-1ubuntu0.4, 2:1.8.13-1ubuntu0.1, 2:1.8.7-1ubuntu0.1
- CVEs
- CVE-2026-88806
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:30 UTC · Revision 1
Source evidence
A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.
osv:UBUNTU-CVE-2026-88806
libx11
Fixed versions: 2:1.6.2-1ubuntu2.1+esm6
libx11
Fixed versions: 2:1.6.3-1ubuntu2.2+esm5
libx11
Fixed versions: 2:1.6.4-3ubuntu0.4+esm3
libx11
Fixed versions: 2:1.6.9-2ubuntu1.6+esm1
libx11
Fixed versions: 2:1.7.5-1ubuntu0.4
libx11
Fixed versions: 2:1.8.7-1ubuntu0.1
libx11
Fixed versions: Not specified
libx11
Fixed versions: 2:1.8.13-1ubuntu0.1
Complete source record
{
"id": "adfaf6a5657fdb9bb74f0bcf1fdaf961a4faa7cf4d37b7c202f9c9861a7736cc",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-88806",
"method": "structured",
"payload": {
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"title": "UBUNTU-CVE-2026-88806",
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{
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{
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{
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{
"name": {
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"evidence": "/affected/3/package/name"
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"fixed_versions": [
{
"value": "2:1.6.9-2ubuntu1.6+esm1",
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],
"affected_versions": [
{
"value": "2:1.6.8-1",
"evidence": "/affected/3/versions"
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{
"value": "2:1.6.9-2",
"evidence": "/affected/3/versions"
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{
"value": "2:1.6.9-2ubuntu1",
"evidence": "/affected/3/versions"
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{
"value": "2:1.6.9-2ubuntu1.1",
"evidence": "/affected/3/versions"
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{
"value": "2:1.6.9-2ubuntu1.2",
"evidence": "/affected/3/versions"
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{
"value": "2:1.6.9-2ubuntu1.5",
"evidence": "/affected/3/versions"
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{
"value": "2:1.6.9-2ubuntu1.6",
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{
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"affected_versions": [
{
"value": "2:1.7.2-1",
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{
"value": "2:1.7.2-2",
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{
"value": "2:1.7.2-2build1",
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{
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{
"value": "2:1.7.5-1ubuntu0.2",
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"value": "2:1.7.5-1ubuntu0.3",
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"name": {
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{
"value": "2:1.8.7-1ubuntu0.1",
"evidence": "/affected/5/ranges"
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],
"affected_versions": [
{
"value": "2:1.8.6-1ubuntu1",
"evidence": "/affected/5/versions"
},
{
"value": "2:1.8.7-1",
"evidence": "/affected/5/versions"
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{
"value": "2:1.8.7-1build1",
"evidence": "/affected/5/versions"
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"name": {
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{
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"affected_versions": [
{
"value": "2:1.8.12-1build1",
"evidence": "/affected/7/versions"
},
{
"value": "2:1.8.12-1build2",
"evidence": "/affected/7/versions"
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{
"value": "2:1.8.13-1",
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"severity": "high",
"structured": {
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"aliases": [
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"metrics": [
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"affected": [
{
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"package": {
"name": "libx11",
"purl": "pkg:deb/ubuntu/libx11?arch=source&distro=esm-infra-legacy%2Ftrusty",
"ecosystem": "Ubuntu:Pro:14.04:LTS"
},
"versions": [
"2:1.6.1-1ubuntu1",
"2:1.6.1-1ubuntu2",
"2:1.6.2-1ubuntu1",
"2:1.6.2-1ubuntu2",
"2:1.6.2-1ubuntu2.1",
"2:1.6.2-1ubuntu2.1+esm1",
"2:1.6.2-1ubuntu2.1+esm2",
"2:1.6.2-1ubuntu2.1+esm3",
"2:1.6.2-1ubuntu2.1+esm4",
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"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88806.json"
},
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"binaries": [
{
"binary_name": "libx11-6",
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},
{
"binary_name": "libx11-data",
"binary_version": "2:1.6.2-1ubuntu2.1+esm6"
},
{
"binary_name": "libx11-xcb1",
"binary_version": "2:1.6.2-1ubuntu2.1+esm6"
}
],
"availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
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"package": {
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"versions": [
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"2:1.6.3-1ubuntu2.2+esm3",
"2:1.6.3-1ubuntu2.2+esm4"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88806.json"
},
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"binaries": [
{
"binary_name": "libx11-6",
"binary_version": "2:1.6.3-1ubuntu2.2+esm5"
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{
"binary_name": "libx11-data",
"binary_version": "2:1.6.3-1ubuntu2.2+esm5"
},
{
"binary_name": "libx11-xcb1",
"binary_version": "2:1.6.3-1ubuntu2.2+esm5"
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],
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}
},
{
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}
],
"package": {
"name": "libx11",
"purl": "pkg:deb/ubuntu/libx11?arch=source&distro=esm-infra%2Fbionic",
"ecosystem": "Ubuntu:Pro:18.04:LTS"
},
"versions": [
"2:1.6.4-3",
"2:1.6.4-3ubuntu0.1",
"2:1.6.4-3ubuntu0.2",
"2:1.6.4-3ubuntu0.3",
"2:1.6.4-3ubuntu0.4",
"2:1.6.4-3ubuntu0.4+esm1",
"2:1.6.4-3ubuntu0.4+esm2"
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"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88806.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libx11-6",
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{
"binary_name": "libx11-data",
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},
{
"binary_name": "libx11-xcb1",
"binary_version": "2:1.6.4-3ubuntu0.4+esm3"
}
],
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
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{
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},
{
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}
]
}
],
"package": {
"name": "libx11",
"purl": "pkg:deb/ubuntu/libx11?arch=source&distro=esm-infra%2Ffocal",
"ecosystem": "Ubuntu:Pro:20.04:LTS"
},
"versions": [
"2:1.6.8-1",
"2:1.6.9-2",
"2:1.6.9-2ubuntu1",
"2:1.6.9-2ubuntu1.1",
"2:1.6.9-2ubuntu1.2",
"2:1.6.9-2ubuntu1.5",
"2:1.6.9-2ubuntu1.6"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88806.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libx11-6",
"binary_version": "2:1.6.9-2ubuntu1.6+esm1"
},
{
"binary_name": "libx11-data",
"binary_version": "2:1.6.9-2ubuntu1.6+esm1"
},
{
"binary_name": "libx11-xcb1",
"binary_version": "2:1.6.9-2ubuntu1.6+esm1"
}
],
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2:1.7.5-1ubuntu0.4"
}
]
}
],
"package": {
"name": "libx11",
"purl": "pkg:deb/ubuntu/libx11?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"2:1.7.2-1",
"2:1.7.2-2",
"2:1.7.2-2build1",
"2:1.7.5-1",
"2:1.7.5-1ubuntu0.2",
"2:1.7.5-1ubuntu0.3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88806.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libx11-6",
"binary_version": "2:1.7.5-1ubuntu0.4"
},
{
"binary_name": "libx11-data",
"binary_version": "2:1.7.5-1ubuntu0.4"
},
{
"binary_name": "libx11-xcb1",
"binary_version": "2:1.7.5-1ubuntu0.4"
}
],
"availability": "No subscription required"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2:1.8.7-1ubuntu0.1"
}
]
}
],
"package": {
"name": "libx11",
"purl": "pkg:deb/ubuntu/libx11?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"2:1.8.6-1ubuntu1",
"2:1.8.7-1",
"2:1.8.7-1build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88806.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libx11-6",
"binary_version": "2:1.8.7-1ubuntu0.1"
},
{
"binary_name": "libx11-data",
"binary_version": "2:1.8.7-1ubuntu0.1"
},
{
"binary_name": "libx11-xcb1",
"binary_version": "2:1.8.7-1ubuntu0.1"
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],
"availability": "No subscription required"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "libx11",
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},
"versions": [
"2:1.8.13-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88806.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libx11-6",
"binary_version": "2:1.8.13-1"
},
{
"binary_name": "libx11-data",
"binary_version": "2:1.8.13-1"
},
{
"binary_name": "libx11-xcb1",
"binary_version": "2:1.8.13-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
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{
"introduced": "0"
},
{
"fixed": "2:1.8.13-1ubuntu0.1"
}
]
}
],
"package": {
"name": "libx11",
"purl": "pkg:deb/ubuntu/libx11?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"2:1.8.12-1build1",
"2:1.8.12-1build2",
"2:1.8.13-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88806.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libx11-6",
"binary_version": "2:1.8.13-1ubuntu0.1"
},
{
"binary_name": "libx11-data",
"binary_version": "2:1.8.13-1ubuntu0.1"
},
{
"binary_name": "libx11-xcb1",
"binary_version": "2:1.8.13-1ubuntu0.1"
}
],
"availability": "No subscription required"
}
}
],
"modified": "2026-10-17T13:01:15.657180454Z",
"provider": "osv",
"upstream": [
"CVE-2026-88806"
],
"references": [
"https://ubuntu.com/security/CVE-2026-88806",
"https://www.cve.org/CVERecord?id=CVE-2026-88806",
"https://gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/309",
"https://ubuntu.com/security/notices/USN-8913-1"
]
},
"related_cves": [
{
"value": "CVE-2026-88806",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 361407,
"published_at": "2026-09-21T14:17:00+00:00"
}