UnratedFix available
xorg-x11-server: Fix of 3 CVEs
Type: advisorySources: OSV
- CVE-2026-33999: fix integer underflow / buffer re-use in _XkbSetCompatMap() leading to out-of-bounds read (ZDI-CAN-28593) - CVE-2026-34001: fix use-after-free in miSyncTriggerFence() leading to server crash and potential memory corruption - CVE-2026-34003: add bounds checking in CheckKeyTypes() to prevent out-of-bounds read (ZDI-CAN-28736)
- Products
- xorg-x11-server-Xdmx, xorg-x11-server-Xephyr, xorg-x11-server-Xnest, xorg-x11-server-Xorg, xorg-x11-server-Xvfb, xorg-x11-server-Xwayland, xorg-x11-server-common, xorg-x11-server-devel, xorg-x11-server-source
- Affected versions
- Not specified
- Fixed versions
- 1.20.4-99.el7_9.tuxcare.els9
- CVEs
- CVE-2026-33999, CVE-2026-34001, CVE-2026-34003
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 11:28 UTC · Revision 1
Source evidence
- CVE-2026-33999: fix integer underflow / buffer re-use in _XkbSetCompatMap() leading to out-of-bounds read (ZDI-CAN-28593) - CVE-2026-34001: fix use-after-free in miSyncTriggerFence() leading to server crash and potential memory corruption - CVE-2026-34003: add bounds checking in CheckKeyTypes() to prevent out-of-bounds read (ZDI-CAN-28736)
osv:CLSA-2026-1784071570
xorg-x11-server-Xdmx
Fixed versions: 1.20.4-99.el7_9.tuxcare.els9
xorg-x11-server-Xephyr
Fixed versions: 1.20.4-99.el7_9.tuxcare.els9
xorg-x11-server-Xnest
Fixed versions: 1.20.4-99.el7_9.tuxcare.els9
xorg-x11-server-Xorg
Fixed versions: 1.20.4-99.el7_9.tuxcare.els9
xorg-x11-server-Xvfb
Fixed versions: 1.20.4-99.el7_9.tuxcare.els9
xorg-x11-server-Xwayland
Fixed versions: 1.20.4-99.el7_9.tuxcare.els9
xorg-x11-server-common
Fixed versions: 1.20.4-99.el7_9.tuxcare.els9
xorg-x11-server-devel
Fixed versions: 1.20.4-99.el7_9.tuxcare.els9
xorg-x11-server-source
Fixed versions: 1.20.4-99.el7_9.tuxcare.els9
Complete source record
{
"id": "5b2a47e66f80603faad0970ce96c7efc4a00aff2028d31015c93eaf4723a033f",
"url": "https://osv.dev/vulnerability/CLSA-2026-1784071570",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "xorg-x11-server: Fix of 3 CVEs",
"summary": "- CVE-2026-33999: fix integer underflow / buffer re-use in _XkbSetCompatMap() leading to out-of-bounds read (ZDI-CAN-28593) - CVE-2026-34001: fix use-after-free in miSyncTriggerFence() leading to server crash and potential memory corruption - CVE-2026-34003: add bounds checking in CheckKeyTypes() to prevent out-of-bounds read (ZDI-CAN-28736)",
"evidence": "osv:CLSA-2026-1784071570",
"products": [
{
"name": {
"value": "xorg-x11-server-Xdmx",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.20.4-99.el7_9.tuxcare.els9",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "xorg-x11-server-Xephyr",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.20.4-99.el7_9.tuxcare.els9",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "xorg-x11-server-Xnest",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.20.4-99.el7_9.tuxcare.els9",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "xorg-x11-server-Xorg",
"evidence": "/affected/3/package/name"
},
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{
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"evidence": "/affected/3/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "xorg-x11-server-Xvfb",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
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{
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"evidence": "/affected/4/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "xorg-x11-server-Xwayland",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.20.4-99.el7_9.tuxcare.els9",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "xorg-x11-server-common",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.20.4-99.el7_9.tuxcare.els9",
"evidence": "/affected/6/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "xorg-x11-server-devel",
"evidence": "/affected/7/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.20.4-99.el7_9.tuxcare.els9",
"evidence": "/affected/7/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "xorg-x11-server-source",
"evidence": "/affected/8/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.20.4-99.el7_9.tuxcare.els9",
"evidence": "/affected/8/ranges"
}
],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "CLSA-2026-1784071570",
"aliases": [
"CLSA-2026-1784071570"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.20.4-99.el7_9.tuxcare.els9"
}
]
}
],
"package": {
"name": "xorg-x11-server-Xdmx",
"purl": "pkg:rpm/tuxcare/xorg-x11-server-Xdmx?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1784071570.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
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{
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}
]
}
],
"package": {
"name": "xorg-x11-server-Xephyr",
"purl": "pkg:rpm/tuxcare/xorg-x11-server-Xephyr?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1784071570.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
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}
]
}
],
"package": {
"name": "xorg-x11-server-Xnest",
"purl": "pkg:rpm/tuxcare/xorg-x11-server-Xnest?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1784071570.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.20.4-99.el7_9.tuxcare.els9"
}
]
}
],
"package": {
"name": "xorg-x11-server-Xorg",
"purl": "pkg:rpm/tuxcare/xorg-x11-server-Xorg?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1784071570.json"
}
},
{
"ranges": [
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},
{
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]
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],
"package": {
"name": "xorg-x11-server-Xvfb",
"purl": "pkg:rpm/tuxcare/xorg-x11-server-Xvfb?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1784071570.json"
}
},
{
"ranges": [
{
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{
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},
{
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}
]
}
],
"package": {
"name": "xorg-x11-server-Xwayland",
"purl": "pkg:rpm/tuxcare/xorg-x11-server-Xwayland?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1784071570.json"
}
},
{
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{
"type": "ECOSYSTEM",
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},
{
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}
]
}
],
"package": {
"name": "xorg-x11-server-common",
"purl": "pkg:rpm/tuxcare/xorg-x11-server-common?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1784071570.json"
}
},
{
"ranges": [
{
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}
]
}
],
"package": {
"name": "xorg-x11-server-devel",
"purl": "pkg:rpm/tuxcare/xorg-x11-server-devel?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1784071570.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.20.4-99.el7_9.tuxcare.els9"
}
]
}
],
"package": {
"name": "xorg-x11-server-source",
"purl": "pkg:rpm/tuxcare/xorg-x11-server-source?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1784071570.json"
}
}
],
"modified": "2026-10-26T09:31:55.411777649Z",
"provider": "osv",
"upstream": [
"CVE-2026-33999",
"CVE-2026-34001",
"CVE-2026-34003"
],
"references": [
"https://errata.tuxcare.com/els_os/oraclelinux7els/CLSA-2026-1784071570.html",
"https://nvd.nist.gov/vuln/detail/CVE-2026-33999",
"https://nvd.nist.gov/vuln/detail/CVE-2026-34001",
"https://nvd.nist.gov/vuln/detail/CVE-2026-34003"
]
},
"related_cves": [
{
"value": "CVE-2026-33999",
"evidence": "/upstream"
},
{
"value": "CVE-2026-34001",
"evidence": "/upstream"
},
{
"value": "CVE-2026-34003",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 448975,
"published_at": "2026-07-14T23:26:24+00:00"
}