UnratedFix available
Fix CVE(s): CVE-2026-63387
Type: advisorySources: OSV
* SECURITY UPDATE: off-by-one stack overflow in dnsname_to_labels() - debian/patches/CVE-2026-63387.patch: fail instead of writing the terminating zero label past the end of the buffer in evdns.c - CVE-2026-63387
- Products
- libevent-2.1-6, libevent-core-2.1-6, libevent-dev, libevent-extra-2.1-6, libevent-openssl-2.1-6, libevent-pthreads-2.1-6
- Affected versions
- Not specified
- Fixed versions
- 2.1.8-stable-4build1+tuxcare.els2
- CVEs
- CVE-2026-63387
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 11:42 UTC · Revision 1
Source evidence
* SECURITY UPDATE: off-by-one stack overflow in dnsname_to_labels() - debian/patches/CVE-2026-63387.patch: fail instead of writing the terminating zero label past the end of the buffer in evdns.c - CVE-2026-63387
osv:CLSA-2026-1791302296
libevent-2.1-6
Fixed versions: 2.1.8-stable-4build1+tuxcare.els2
libevent-core-2.1-6
Fixed versions: 2.1.8-stable-4build1+tuxcare.els2
libevent-dev
Fixed versions: 2.1.8-stable-4build1+tuxcare.els2
libevent-extra-2.1-6
Fixed versions: 2.1.8-stable-4build1+tuxcare.els2
libevent-openssl-2.1-6
Fixed versions: 2.1.8-stable-4build1+tuxcare.els2
libevent-pthreads-2.1-6
Fixed versions: 2.1.8-stable-4build1+tuxcare.els2
Complete source record
{
"id": "17f060d8d89abb6ba3460ac26d71409cfd8c4090086f14481ccbc60a840181b7",
"url": "https://osv.dev/vulnerability/CLSA-2026-1791302296",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Fix CVE(s): CVE-2026-63387",
"summary": "* SECURITY UPDATE: off-by-one stack overflow in dnsname_to_labels() - debian/patches/CVE-2026-63387.patch: fail instead of writing the terminating zero label past the end of the buffer in evdns.c - CVE-2026-63387",
"evidence": "osv:CLSA-2026-1791302296",
"products": [
{
"name": {
"value": "libevent-2.1-6",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.1.8-stable-4build1+tuxcare.els2",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "libevent-core-2.1-6",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.1.8-stable-4build1+tuxcare.els2",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "libevent-dev",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.1.8-stable-4build1+tuxcare.els2",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "libevent-extra-2.1-6",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.1.8-stable-4build1+tuxcare.els2",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "libevent-openssl-2.1-6",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.1.8-stable-4build1+tuxcare.els2",
"evidence": "/affected/4/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "libevent-pthreads-2.1-6",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.1.8-stable-4build1+tuxcare.els2",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "CLSA-2026-1791302296",
"aliases": [
"CLSA-2026-1791302296"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.1.8-stable-4build1+tuxcare.els2"
}
]
}
],
"package": {
"name": "libevent-2.1-6",
"purl": "pkg:deb/tuxcare/libevent-2.1-6?distro=ubuntu-18.04",
"ecosystem": "TuxCare:Ubuntu:18.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu18.04els/CLSA-2026-1791302296.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.1.8-stable-4build1+tuxcare.els2"
}
]
}
],
"package": {
"name": "libevent-core-2.1-6",
"purl": "pkg:deb/tuxcare/libevent-core-2.1-6?distro=ubuntu-18.04",
"ecosystem": "TuxCare:Ubuntu:18.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu18.04els/CLSA-2026-1791302296.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.1.8-stable-4build1+tuxcare.els2"
}
]
}
],
"package": {
"name": "libevent-dev",
"purl": "pkg:deb/tuxcare/libevent-dev?distro=ubuntu-18.04",
"ecosystem": "TuxCare:Ubuntu:18.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu18.04els/CLSA-2026-1791302296.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.1.8-stable-4build1+tuxcare.els2"
}
]
}
],
"package": {
"name": "libevent-extra-2.1-6",
"purl": "pkg:deb/tuxcare/libevent-extra-2.1-6?distro=ubuntu-18.04",
"ecosystem": "TuxCare:Ubuntu:18.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu18.04els/CLSA-2026-1791302296.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.1.8-stable-4build1+tuxcare.els2"
}
]
}
],
"package": {
"name": "libevent-openssl-2.1-6",
"purl": "pkg:deb/tuxcare/libevent-openssl-2.1-6?distro=ubuntu-18.04",
"ecosystem": "TuxCare:Ubuntu:18.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu18.04els/CLSA-2026-1791302296.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.1.8-stable-4build1+tuxcare.els2"
}
]
}
],
"package": {
"name": "libevent-pthreads-2.1-6",
"purl": "pkg:deb/tuxcare/libevent-pthreads-2.1-6?distro=ubuntu-18.04",
"ecosystem": "TuxCare:Ubuntu:18.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu18.04els/CLSA-2026-1791302296.json"
}
}
],
"modified": "2026-10-26T09:32:04.330001705Z",
"provider": "osv",
"upstream": [
"CVE-2026-63387"
],
"references": [
"https://errata.tuxcare.com/els_os/ubuntu18.04els/CLSA-2026-1791302296.html",
"https://nvd.nist.gov/vuln/detail/CVE-2026-63387"
]
},
"related_cves": [
{
"value": "CVE-2026-63387",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 449605,
"published_at": "2026-10-06T15:58:26+00:00"
}