UnratedFix available
tigervnc: Fix of 6 CVEs
Type: advisorySources: OSV
- CVE-2026-50256: fix stack overflow in font alias resolution by widening XLFDMAXFONTNAMELEN to match libXfont2 MAXFONTNAMELEN (bundled Xvnc xserver) - CVE-2026-50257: fix use-after-free of sync fences in miSyncDestroyFence - CVE-2026-50258: fix stack overflow in XKB CheckKeyTypes - CVE-2026-50259: fix stack overflow in XKB _XkbSetMapChecks key-type check - CVE-2026-50260: fix use-after-free of sync counters in FreeCounter - CVE-2026-50261: fix use-after-free in SyncChangeCounter - patches backported into the bundled xserver 21.1.3 tree, reused from the xorg-x11-server-Xwayland sibling change
- Products
- tigervnc, tigervnc-icons, tigervnc-license, tigervnc-selinux, tigervnc-server, tigervnc-server-minimal, tigervnc-server-module
- Affected versions
- Not specified
- Fixed versions
- 1.12.0-13.el9_2.tuxcare.els25
- CVEs
- 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, 10:41 UTC · Revision 1
Source evidence
- CVE-2026-50256: fix stack overflow in font alias resolution by widening XLFDMAXFONTNAMELEN to match libXfont2 MAXFONTNAMELEN (bundled Xvnc xserver) - CVE-2026-50257: fix use-after-free of sync fences in miSyncDestroyFence - CVE-2026-50258: fix stack overflow in XKB CheckKeyTypes - CVE-2026-50259: fix stack overflow in XKB _XkbSetMapChecks key-type check - CVE-2026-50260: fix use-after-free of sync counters in FreeCounter - CVE-2026-50261: fix use-after-free in SyncChangeCounter - patches backported into the bundled xserver 21.1.3 tree, reused from the xorg-x11-server-Xwayland sibling change
osv:CLSA-2026-1782904895
tigervnc
Fixed versions: 1.12.0-13.el9_2.tuxcare.els25
tigervnc-icons
Fixed versions: 1.12.0-13.el9_2.tuxcare.els25
tigervnc-license
Fixed versions: 1.12.0-13.el9_2.tuxcare.els25
tigervnc-selinux
Fixed versions: 1.12.0-13.el9_2.tuxcare.els25
tigervnc-server
Fixed versions: 1.12.0-13.el9_2.tuxcare.els25
tigervnc-server-minimal
Fixed versions: 1.12.0-13.el9_2.tuxcare.els25
tigervnc-server-module
Fixed versions: 1.12.0-13.el9_2.tuxcare.els25
Complete source record
{
"id": "ab60436c3eb4fe1227ec1c7661ea1f1341d3d381c3d4e56f237e36143eb3d8a7",
"url": "https://osv.dev/vulnerability/CLSA-2026-1782904895",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "tigervnc: Fix of 6 CVEs",
"summary": "- CVE-2026-50256: fix stack overflow in font alias resolution by widening XLFDMAXFONTNAMELEN to match libXfont2 MAXFONTNAMELEN (bundled Xvnc xserver) - CVE-2026-50257: fix use-after-free of sync fences in miSyncDestroyFence - CVE-2026-50258: fix stack overflow in XKB CheckKeyTypes - CVE-2026-50259: fix stack overflow in XKB _XkbSetMapChecks key-type check - CVE-2026-50260: fix use-after-free of sync counters in FreeCounter - CVE-2026-50261: fix use-after-free in SyncChangeCounter - patches backported into the bundled xserver 21.1.3 tree, reused from the xorg-x11-server-Xwayland sibling change",
"evidence": "osv:CLSA-2026-1782904895",
"products": [
{
"name": {
"value": "tigervnc",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.12.0-13.el9_2.tuxcare.els25",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-icons",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.12.0-13.el9_2.tuxcare.els25",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-license",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.12.0-13.el9_2.tuxcare.els25",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-selinux",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.12.0-13.el9_2.tuxcare.els25",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-server",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.12.0-13.el9_2.tuxcare.els25",
"evidence": "/affected/4/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-server-minimal",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.12.0-13.el9_2.tuxcare.els25",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "tigervnc-server-module",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.12.0-13.el9_2.tuxcare.els25",
"evidence": "/affected/6/ranges"
}
],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "CLSA-2026-1782904895",
"aliases": [
"CLSA-2026-1782904895"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.12.0-13.el9_2.tuxcare.els25"
}
]
}
],
"package": {
"name": "tigervnc",
"purl": "pkg:rpm/tuxcare/tigervnc?distro=almalinux-9.2",
"ecosystem": "TuxCare:AlmaLinux:9.2"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.2esu/CLSA-2026-1782904895.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.12.0-13.el9_2.tuxcare.els25"
}
]
}
],
"package": {
"name": "tigervnc-icons",
"purl": "pkg:rpm/tuxcare/tigervnc-icons?distro=almalinux-9.2",
"ecosystem": "TuxCare:AlmaLinux:9.2"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.2esu/CLSA-2026-1782904895.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.12.0-13.el9_2.tuxcare.els25"
}
]
}
],
"package": {
"name": "tigervnc-license",
"purl": "pkg:rpm/tuxcare/tigervnc-license?distro=almalinux-9.2",
"ecosystem": "TuxCare:AlmaLinux:9.2"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.2esu/CLSA-2026-1782904895.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.12.0-13.el9_2.tuxcare.els25"
}
]
}
],
"package": {
"name": "tigervnc-selinux",
"purl": "pkg:rpm/tuxcare/tigervnc-selinux?distro=almalinux-9.2",
"ecosystem": "TuxCare:AlmaLinux:9.2"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.2esu/CLSA-2026-1782904895.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.12.0-13.el9_2.tuxcare.els25"
}
]
}
],
"package": {
"name": "tigervnc-server",
"purl": "pkg:rpm/tuxcare/tigervnc-server?distro=almalinux-9.2",
"ecosystem": "TuxCare:AlmaLinux:9.2"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.2esu/CLSA-2026-1782904895.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.12.0-13.el9_2.tuxcare.els25"
}
]
}
],
"package": {
"name": "tigervnc-server-minimal",
"purl": "pkg:rpm/tuxcare/tigervnc-server-minimal?distro=almalinux-9.2",
"ecosystem": "TuxCare:AlmaLinux:9.2"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.2esu/CLSA-2026-1782904895.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.12.0-13.el9_2.tuxcare.els25"
}
]
}
],
"package": {
"name": "tigervnc-server-module",
"purl": "pkg:rpm/tuxcare/tigervnc-server-module?distro=almalinux-9.2",
"ecosystem": "TuxCare:AlmaLinux:9.2"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.2esu/CLSA-2026-1782904895.json"
}
}
],
"modified": "2026-10-26T09:30:24.048222704Z",
"provider": "osv",
"upstream": [
"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/almalinux9.2esu/CLSA-2026-1782904895.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-2026-50256",
"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": 447020,
"published_at": "2026-07-01T11:21:57+00:00"
}