HighFix available
libssh2 — security advisory
libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 client.
- Products
- libssh2
- Affected versions
- 1.10.0-3, 1.11.1-1, 1.11.1-1+deb13u1, 1.11.1-2, 1.11.1-3, 1.11.1-4, 1.11.1-5
- Fixed versions
- 1.10.0-3+deb12u1, 1.11.1-1+deb13u2, 1.11.1-6
- CVEs
- CVE-2026-58051
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 12:18 UTC · Revision 2
Source evidence
libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 client.
osv:DEBIAN-CVE-2026-58051
libssh2
Fixed versions: 1.10.0-3+deb12u1
libssh2
Fixed versions: 1.11.1-1+deb13u2
libssh2
Fixed versions: 1.11.1-6
Complete source record
{
"id": "3f689c05a62290e37fd74ad58ec1bed07c32031975b908dfa170b8b7bfe94833",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-58051",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-58051",
"summary": "libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 client.",
"evidence": "osv:DEBIAN-CVE-2026-58051",
"products": [
{
"name": {
"value": "libssh2",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.10.0-3+deb12u1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "1.10.0-3",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "libssh2",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.11.1-1+deb13u2",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": [
{
"value": "1.11.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.11.1-1+deb13u1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "libssh2",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.11.1-6",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "1.11.1-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.11.1-2",
"evidence": "/affected/2/versions"
},
{
"value": "1.11.1-3",
"evidence": "/affected/2/versions"
},
{
"value": "1.11.1-4",
"evidence": "/affected/2/versions"
},
{
"value": "1.11.1-5",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2026-58051",
"aliases": [
"DEBIAN-CVE-2026-58051"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.10.0-3+deb12u1"
}
]
}
],
"package": {
"name": "libssh2",
"purl": "pkg:deb/debian/libssh2?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"1.10.0-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-58051.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.11.1-1+deb13u2"
}
]
}
],
"package": {
"name": "libssh2",
"purl": "pkg:deb/debian/libssh2?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"1.11.1-1",
"1.11.1-1+deb13u1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-58051.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.11.1-6"
}
]
}
],
"package": {
"name": "libssh2",
"purl": "pkg:deb/debian/libssh2?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"1.11.1-1",
"1.11.1-2",
"1.11.1-3",
"1.11.1-4",
"1.11.1-5"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-58051.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-26T11:47:30.296504984Z",
"provider": "osv",
"upstream": [
"CVE-2026-58051"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-58051"
]
},
"related_cves": [
{
"value": "CVE-2026-58051",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 450815,
"published_at": "2026-06-28T02:16:32.153+00:00"
}