tigervnc: Fix of 6 CVEs
- CVE-2026-50256: fix stack buffer overflow in font alias resolution in the bundled xorg-x11-server source by raising XLFDMAXFONTNAMELEN to libXfont2's MAXFONTNAMELEN and rejecting over-long resolved names - CVE-2026-50257: fix use-after-free in miSyncDestroyFence() in the bundled xorg-x11-server source - CVE-2026-50258: reject XKB key types whose numLevels exceeds XkbMaxShiftLevel in the bundled xorg-x11-server source to prevent a stack buffer overflow in XkbKeyTypesForCoreSymbols() - CVE-2026-50259: clamp nMaps to the mapWidths[] buffer size in CheckKeyTypes() in the bundled xorg-x11-server source to prevent a stack buffer overflow from XkbSetMap requests - CVE-2026-50260: fix use-after-free in FreeCounter() in the bundled xorg-x11-server source - CVE-2026-50261: fix use-after-free in SyncChangeCounter() in the bundled xorg-x11-server source by restarting trigger list iteration after a trigger fires - Dropped the local xorg-CVE-2026-33999/34000/34001/34002/34003 patches and require xorg-x11-server-source >= 1.20.4-99.el7_9.tuxcare.els10 instead; those fixes are now carried by the xorg-x11-server source package, and applying them again here failed %prep
- Products
- tigervnc, tigervnc-icons, tigervnc-license, tigervnc-server, tigervnc-server-applet, tigervnc-server-minimal, tigervnc-server-module
- Affected versions
- Not specified
- Fixed versions
- 1.8.0-33.0.7.el7_9.tuxcare.els7
- CVEs
- CVE-2026-33999, CVE-2026-50256, CVE-2026-50257, CVE-2026-50258, CVE-2026-50259, CVE-2026-50260, CVE-2026-50261
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 11:55 UTC · Revision 1
Source evidence
- CVE-2026-50256: fix stack buffer overflow in font alias resolution in the bundled xorg-x11-server source by raising XLFDMAXFONTNAMELEN to libXfont2's MAXFONTNAMELEN and rejecting over-long resolved names - CVE-2026-50257: fix use-after-free in miSyncDestroyFence() in the bundled xorg-x11-server source - CVE-2026-50258: reject XKB key types whose numLevels exceeds XkbMaxShiftLevel in the bundled xorg-x11-server source to prevent a stack buffer overflow in XkbKeyTypesForCoreSymbols() - CVE-2026-50259: clamp nMaps to the mapWidths[] buffer size in CheckKeyTypes() in the bundled xorg-x11-server source to prevent a stack buffer overflow from XkbSetMap requests - CVE-2026-50260: fix use-after-free in FreeCounter() in the bundled xorg-x11-server source - CVE-2026-50261: fix use-after-free in SyncChangeCounter() in the bundled xorg-x11-server source by restarting trigger list iteration after a trigger fires - Dropped the local xorg-CVE-2026-33999/34000/34001/34002/34003 patches and require xorg-x11-server-source >= 1.20.4-99.el7_9.tuxcare.els10 instead; those fixes are now carried by the xorg-x11-server source package, and applying them again here failed %prep
osv:CLSA-2026-1785917589
tigervnc
Fixed versions: 1.8.0-33.0.7.el7_9.tuxcare.els7
tigervnc-icons
Fixed versions: 1.8.0-33.0.7.el7_9.tuxcare.els7
tigervnc-license
Fixed versions: 1.8.0-33.0.7.el7_9.tuxcare.els7
tigervnc-server
Fixed versions: 1.8.0-33.0.7.el7_9.tuxcare.els7
tigervnc-server-applet
Fixed versions: 1.8.0-33.0.7.el7_9.tuxcare.els7
tigervnc-server-minimal
Fixed versions: 1.8.0-33.0.7.el7_9.tuxcare.els7
tigervnc-server-module
Fixed versions: 1.8.0-33.0.7.el7_9.tuxcare.els7
Complete source record
{
"id": "7863a8d7ed34a725eb678c2fe7c58d3306a5cdf3338b8875fd7a6ef84af0e375",
"url": "https://osv.dev/vulnerability/CLSA-2026-1785917589",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "tigervnc: Fix of 6 CVEs",
"summary": "- CVE-2026-50256: fix stack buffer overflow in font alias resolution in the bundled xorg-x11-server source by raising XLFDMAXFONTNAMELEN to libXfont2's MAXFONTNAMELEN and rejecting over-long resolved names - CVE-2026-50257: fix use-after-free in miSyncDestroyFence() in the bundled xorg-x11-server source - CVE-2026-50258: reject XKB key types whose numLevels exceeds XkbMaxShiftLevel in the bundled xorg-x11-server source to prevent a stack buffer overflow in XkbKeyTypesForCoreSymbols() - CVE-2026-50259: clamp nMaps to the mapWidths[] buffer size in CheckKeyTypes() in the bundled xorg-x11-server source to prevent a stack buffer overflow from XkbSetMap requests - CVE-2026-50260: fix use-after-free in FreeCounter() in the bundled xorg-x11-server source - CVE-2026-50261: fix use-after-free in SyncChangeCounter() in the bundled xorg-x11-server source by restarting trigger list iteration after a trigger fires - Dropped the local xorg-CVE-2026-33999/34000/34001/34002/34003 patches and require xorg-x11-server-source >= 1.20.4-99.el7_9.tuxcare.els10 instead; those fixes are now carried by the xorg-x11-server source package, and applying them again here failed %prep",
"evidence": "osv:CLSA-2026-1785917589",
"products": [
{
"name": {
"value": "tigervnc",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.8.0-33.0.7.el7_9.tuxcare.els7",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-icons",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.8.0-33.0.7.el7_9.tuxcare.els7",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-license",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.8.0-33.0.7.el7_9.tuxcare.els7",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-server",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.8.0-33.0.7.el7_9.tuxcare.els7",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-server-applet",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.8.0-33.0.7.el7_9.tuxcare.els7",
"evidence": "/affected/4/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-server-minimal",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.8.0-33.0.7.el7_9.tuxcare.els7",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-server-module",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.8.0-33.0.7.el7_9.tuxcare.els7",
"evidence": "/affected/6/ranges"
}
],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "CLSA-2026-1785917589",
"aliases": [
"CLSA-2026-1785917589"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.0-33.0.7.el7_9.tuxcare.els7"
}
]
}
],
"package": {
"name": "tigervnc",
"purl": "pkg:rpm/tuxcare/tigervnc?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1785917589.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.0-33.0.7.el7_9.tuxcare.els7"
}
]
}
],
"package": {
"name": "tigervnc-icons",
"purl": "pkg:rpm/tuxcare/tigervnc-icons?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1785917589.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.0-33.0.7.el7_9.tuxcare.els7"
}
]
}
],
"package": {
"name": "tigervnc-license",
"purl": "pkg:rpm/tuxcare/tigervnc-license?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1785917589.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.0-33.0.7.el7_9.tuxcare.els7"
}
]
}
],
"package": {
"name": "tigervnc-server",
"purl": "pkg:rpm/tuxcare/tigervnc-server?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1785917589.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.0-33.0.7.el7_9.tuxcare.els7"
}
]
}
],
"package": {
"name": "tigervnc-server-applet",
"purl": "pkg:rpm/tuxcare/tigervnc-server-applet?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1785917589.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.0-33.0.7.el7_9.tuxcare.els7"
}
]
}
],
"package": {
"name": "tigervnc-server-minimal",
"purl": "pkg:rpm/tuxcare/tigervnc-server-minimal?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1785917589.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.0-33.0.7.el7_9.tuxcare.els7"
}
]
}
],
"package": {
"name": "tigervnc-server-module",
"purl": "pkg:rpm/tuxcare/tigervnc-server-module?distro=oraclelinux-7",
"ecosystem": "TuxCare:OracleLinux:7"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/oraclelinux7els/CLSA-2026-1785917589.json"
}
}
],
"modified": "2026-10-26T09:43:45.574385951Z",
"provider": "osv",
"upstream": [
"CVE-2026-33999",
"CVE-2026-50256",
"CVE-2026-50257",
"CVE-2026-50258",
"CVE-2026-50259",
"CVE-2026-50260",
"CVE-2026-50261"
],
"references": [
"https://errata.tuxcare.com/els_os/oraclelinux7els/CLSA-2026-1785917589.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"
]
},
"related_cves": [
{
"value": "CVE-2026-33999",
"evidence": "/upstream"
},
{
"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"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 450122,
"published_at": "2026-08-05T08:13:26+00:00"
}