libssh2 — security advisory
A flaw was found in libssh2 before 1.8.1 creating a vulnerability on the SSH client side. A server could send a multiple keyboard interactive response messages whose total length are greater than unsigned char max characters. This value is used by the SSH client as an index to copy memory causing in an out of bounds memory write error.
- Products
- libssh2
- Affected versions
- Not specified
- Fixed versions
- 1.8.0-2.1
- CVEs
- CVE-2019-3863
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 14:22 UTC · Revision 1
Source evidence
A flaw was found in libssh2 before 1.8.1 creating a vulnerability on the SSH client side. A server could send a multiple keyboard interactive response messages whose total length are greater than unsigned char max characters. This value is used by the SSH client as an index to copy memory causing in an out of bounds memory write error.
osv:DEBIAN-CVE-2019-3863
libssh2
Fixed versions: 1.8.0-2.1
libssh2
Fixed versions: 1.8.0-2.1
libssh2
Fixed versions: 1.8.0-2.1
Complete source record
{
"id": "9035817660ee324f376c9d351e0fb72dee37cb1ae1a1d1e56340dd13752e13d6",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2019-3863",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2019-3863",
"summary": "A flaw was found in libssh2 before 1.8.1 creating a vulnerability on the SSH client side. A server could send a multiple keyboard interactive response messages whose total length are greater than unsigned char max characters. This value is used by the SSH client as an index to copy memory causing in an out of bounds memory write error.",
"evidence": "osv:DEBIAN-CVE-2019-3863",
"products": [
{
"name": {
"value": "libssh2",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.8.0-2.1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "libssh2",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.8.0-2.1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "libssh2",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.8.0-2.1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2019-3863",
"aliases": [
"DEBIAN-CVE-2019-3863"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.0-2.1"
}
]
}
],
"package": {
"name": "libssh2",
"purl": "pkg:deb/debian/libssh2?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2019-3863.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.0-2.1"
}
]
}
],
"package": {
"name": "libssh2",
"purl": "pkg:deb/debian/libssh2?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2019-3863.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.0-2.1"
}
]
}
],
"package": {
"name": "libssh2",
"purl": "pkg:deb/debian/libssh2?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2019-3863.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-15T07:47:31.407243194Z",
"provider": "osv",
"upstream": [
"CVE-2019-3863"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2019-3863"
]
},
"related_cves": [
{
"value": "CVE-2019-3863",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 322203,
"published_at": "2019-03-25T18:29:01.59+00:00"
}