tigervnc: Fix of 8 CVEs
- CVE-2026-50256: increase XLFDMAXFONTNAMELEN to 1024 and bound-check resolved font-alias names before copying into the pattern buffers, preventing a stack overflow during alias resolution (bundled xorg-server) - CVE-2026-50257, CVE-2026-50260: fix use-after-free when destroying sync fences (miSyncDestroyFence) and counters (FreeCounter) whose trigger list is shared across an Await group (bundled xorg-server) - CVE-2026-50258: reject XKB key types whose numLevels exceeds XkbMaxShiftLevel in CheckKeyTypes, preventing a stack overflow in XkbKeyTypesForCoreSymbols (bundled xorg-server) - CVE-2026-50259: clamp nMaps to the mapWidths buffer size in CheckKeyTypes so an XkbSetMap resize request cannot overflow the stack buffer (bundled xorg-server) - CVE-2026-50261: restart trigger-list iteration in SyncChangeCounter after a trigger fires, preventing a use-after-free of freed trigger nodes (bundled xorg-server) - CVE-2026-50262: enforce an exact request size in glx ChangeDrawableAttributes, fixing a reversed length check that allowed an out-of-bounds read/write (bundled xorg-server) - CVE-2026-50263: re-fetch the screen-saver screen private after CheckScreenPrivate in CreateSaverWindow, preventing a use-after-free (bundled xorg-server)
- Products
- tigervnc, tigervnc-icons, tigervnc-license, tigervnc-selinux, tigervnc-server, tigervnc-server-minimal, tigervnc-server-module
- Affected versions
- Not specified
- Fixed versions
- 1.14.1-9.el9_6.tuxcare.els4
- CVEs
- CVE-2026-50256, CVE-2026-50257, CVE-2026-50258, CVE-2026-50259, CVE-2026-50260, CVE-2026-50261, CVE-2026-50262, CVE-2026-50263
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 11:57 UTC · Revision 1
Source evidence
- CVE-2026-50256: increase XLFDMAXFONTNAMELEN to 1024 and bound-check resolved font-alias names before copying into the pattern buffers, preventing a stack overflow during alias resolution (bundled xorg-server) - CVE-2026-50257, CVE-2026-50260: fix use-after-free when destroying sync fences (miSyncDestroyFence) and counters (FreeCounter) whose trigger list is shared across an Await group (bundled xorg-server) - CVE-2026-50258: reject XKB key types whose numLevels exceeds XkbMaxShiftLevel in CheckKeyTypes, preventing a stack overflow in XkbKeyTypesForCoreSymbols (bundled xorg-server) - CVE-2026-50259: clamp nMaps to the mapWidths buffer size in CheckKeyTypes so an XkbSetMap resize request cannot overflow the stack buffer (bundled xorg-server) - CVE-2026-50261: restart trigger-list iteration in SyncChangeCounter after a trigger fires, preventing a use-after-free of freed trigger nodes (bundled xorg-server) - CVE-2026-50262: enforce an exact request size in glx ChangeDrawableAttributes, fixing a reversed length check that allowed an out-of-bounds read/write (bundled xorg-server) - CVE-2026-50263: re-fetch the screen-saver screen private after CheckScreenPrivate in CreateSaverWindow, preventing a use-after-free (bundled xorg-server)
osv:CLSA-2026-1782812906
tigervnc
Fixed versions: 1.14.1-9.el9_6.tuxcare.els4
tigervnc-icons
Fixed versions: 1.14.1-9.el9_6.tuxcare.els4
tigervnc-license
Fixed versions: 1.14.1-9.el9_6.tuxcare.els4
tigervnc-selinux
Fixed versions: 1.14.1-9.el9_6.tuxcare.els4
tigervnc-server
Fixed versions: 1.14.1-9.el9_6.tuxcare.els4
tigervnc-server-minimal
Fixed versions: 1.14.1-9.el9_6.tuxcare.els4
tigervnc-server-module
Fixed versions: 1.14.1-9.el9_6.tuxcare.els4
Complete source record
{
"id": "4caf63cf7e7acf227241c4d4114c03fff63bcfc3396bbba954cfb06e55cfe84c",
"url": "https://osv.dev/vulnerability/CLSA-2026-1782812906",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "tigervnc: Fix of 8 CVEs",
"summary": "- CVE-2026-50256: increase XLFDMAXFONTNAMELEN to 1024 and bound-check resolved font-alias names before copying into the pattern buffers, preventing a stack overflow during alias resolution (bundled xorg-server) - CVE-2026-50257, CVE-2026-50260: fix use-after-free when destroying sync fences (miSyncDestroyFence) and counters (FreeCounter) whose trigger list is shared across an Await group (bundled xorg-server) - CVE-2026-50258: reject XKB key types whose numLevels exceeds XkbMaxShiftLevel in CheckKeyTypes, preventing a stack overflow in XkbKeyTypesForCoreSymbols (bundled xorg-server) - CVE-2026-50259: clamp nMaps to the mapWidths buffer size in CheckKeyTypes so an XkbSetMap resize request cannot overflow the stack buffer (bundled xorg-server) - CVE-2026-50261: restart trigger-list iteration in SyncChangeCounter after a trigger fires, preventing a use-after-free of freed trigger nodes (bundled xorg-server) - CVE-2026-50262: enforce an exact request size in glx ChangeDrawableAttributes, fixing a reversed length check that allowed an out-of-bounds read/write (bundled xorg-server) - CVE-2026-50263: re-fetch the screen-saver screen private after CheckScreenPrivate in CreateSaverWindow, preventing a use-after-free (bundled xorg-server)",
"evidence": "osv:CLSA-2026-1782812906",
"products": [
{
"name": {
"value": "tigervnc",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.14.1-9.el9_6.tuxcare.els4",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-icons",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.14.1-9.el9_6.tuxcare.els4",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-license",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.14.1-9.el9_6.tuxcare.els4",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-selinux",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.14.1-9.el9_6.tuxcare.els4",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-server",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.14.1-9.el9_6.tuxcare.els4",
"evidence": "/affected/4/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-server-minimal",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.14.1-9.el9_6.tuxcare.els4",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-server-module",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.14.1-9.el9_6.tuxcare.els4",
"evidence": "/affected/6/ranges"
}
],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "CLSA-2026-1782812906",
"aliases": [
"CLSA-2026-1782812906"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.14.1-9.el9_6.tuxcare.els4"
}
]
}
],
"package": {
"name": "tigervnc",
"purl": "pkg:rpm/tuxcare/tigervnc?distro=almalinux-9.6",
"ecosystem": "TuxCare:AlmaLinux:9.6"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.6esu/CLSA-2026-1782812906.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.14.1-9.el9_6.tuxcare.els4"
}
]
}
],
"package": {
"name": "tigervnc-icons",
"purl": "pkg:rpm/tuxcare/tigervnc-icons?distro=almalinux-9.6",
"ecosystem": "TuxCare:AlmaLinux:9.6"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.6esu/CLSA-2026-1782812906.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.14.1-9.el9_6.tuxcare.els4"
}
]
}
],
"package": {
"name": "tigervnc-license",
"purl": "pkg:rpm/tuxcare/tigervnc-license?distro=almalinux-9.6",
"ecosystem": "TuxCare:AlmaLinux:9.6"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.6esu/CLSA-2026-1782812906.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.14.1-9.el9_6.tuxcare.els4"
}
]
}
],
"package": {
"name": "tigervnc-selinux",
"purl": "pkg:rpm/tuxcare/tigervnc-selinux?distro=almalinux-9.6",
"ecosystem": "TuxCare:AlmaLinux:9.6"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.6esu/CLSA-2026-1782812906.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.14.1-9.el9_6.tuxcare.els4"
}
]
}
],
"package": {
"name": "tigervnc-server",
"purl": "pkg:rpm/tuxcare/tigervnc-server?distro=almalinux-9.6",
"ecosystem": "TuxCare:AlmaLinux:9.6"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.6esu/CLSA-2026-1782812906.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.14.1-9.el9_6.tuxcare.els4"
}
]
}
],
"package": {
"name": "tigervnc-server-minimal",
"purl": "pkg:rpm/tuxcare/tigervnc-server-minimal?distro=almalinux-9.6",
"ecosystem": "TuxCare:AlmaLinux:9.6"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.6esu/CLSA-2026-1782812906.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.14.1-9.el9_6.tuxcare.els4"
}
]
}
],
"package": {
"name": "tigervnc-server-module",
"purl": "pkg:rpm/tuxcare/tigervnc-server-module?distro=almalinux-9.6",
"ecosystem": "TuxCare:AlmaLinux:9.6"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.6esu/CLSA-2026-1782812906.json"
}
}
],
"modified": "2026-10-26T09:43:53.223485102Z",
"provider": "osv",
"upstream": [
"CVE-2026-50256",
"CVE-2026-50257",
"CVE-2026-50258",
"CVE-2026-50259",
"CVE-2026-50260",
"CVE-2026-50261",
"CVE-2026-50262",
"CVE-2026-50263"
],
"references": [
"https://errata.tuxcare.com/els_os/tuxcare9.6esu/CLSA-2026-1782812906.html",
"https://nvd.nist.gov/vuln/detail/CVE-2026-50256",
"https://nvd.nist.gov/vuln/detail/CVE-2026-50257",
"https://nvd.nist.gov/vuln/detail/CVE-2026-50258",
"https://nvd.nist.gov/vuln/detail/CVE-2026-50259",
"https://nvd.nist.gov/vuln/detail/CVE-2026-50260",
"https://nvd.nist.gov/vuln/detail/CVE-2026-50261",
"https://nvd.nist.gov/vuln/detail/CVE-2026-50262",
"https://nvd.nist.gov/vuln/detail/CVE-2026-50263"
]
},
"related_cves": [
{
"value": "CVE-2026-50256",
"evidence": "/upstream"
},
{
"value": "CVE-2026-50257",
"evidence": "/upstream"
},
{
"value": "CVE-2026-50258",
"evidence": "/upstream"
},
{
"value": "CVE-2026-50259",
"evidence": "/upstream"
},
{
"value": "CVE-2026-50260",
"evidence": "/upstream"
},
{
"value": "CVE-2026-50261",
"evidence": "/upstream"
},
{
"value": "CVE-2026-50262",
"evidence": "/upstream"
},
{
"value": "CVE-2026-50263",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 450217,
"published_at": "2026-06-30T09:48:54+00:00"
}