CriticalFix available
gnutls28 — security advisory
A flaw was found in gnutls. Servers configured with RSA-PSK (Rivest–Shamir–Adleman – Pre-Shared Key) wrongfully matched usernames containing a NUL character with truncated usernames. A remote attacker could exploit this by sending a specially crafted username, leading to an authentication bypass. This vulnerability allows an attacker to gain unauthorized access by circumventing the authentication process.
- Products
- gnutls28
- Affected versions
- 3.7.9-2, 3.7.9-2+deb12u1, 3.7.9-2+deb12u2, 3.7.9-2+deb12u3, 3.7.9-2+deb12u4, 3.7.9-2+deb12u5, 3.7.9-2+deb12u6, 3.8.10-1, 3.8.10-2, 3.8.10-3, 3.8.11-1, 3.8.11-2, 3.8.11-3, 3.8.12-1, 3.8.12-2, 3.8.12-3, 3.8.12-4, 3.8.9-3, 3.8.9-3+deb13u1, 3.8.9-3+deb13u2, 3.8.9-3+deb13u3
- Fixed versions
- 3.7.9-2+deb12u7, 3.8.13-1, 3.8.9-3+deb13u4
- CVEs
- CVE-2026-42010
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 17:41 UTC · Revision 1
Source evidence
A flaw was found in gnutls. Servers configured with RSA-PSK (Rivest–Shamir–Adleman – Pre-Shared Key) wrongfully matched usernames containing a NUL character with truncated usernames. A remote attacker could exploit this by sending a specially crafted username, leading to an authentication bypass. This vulnerability allows an attacker to gain unauthorized access by circumventing the authentication process.
osv:DEBIAN-CVE-2026-42010
gnutls28
Fixed versions: 3.7.9-2+deb12u7
gnutls28
Fixed versions: 3.8.9-3+deb13u4
gnutls28
Fixed versions: 3.8.13-1
Complete source record
{
"id": "55c9a282022149e994f0cbc481d9563d65d6ceffa4cc12a347de4d0373c8c205",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-42010",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-42010",
"summary": "A flaw was found in gnutls. Servers configured with RSA-PSK (Rivest–Shamir–Adleman – Pre-Shared Key) wrongfully matched usernames containing a NUL character with truncated usernames. A remote attacker could exploit this by sending a specially crafted username, leading to an authentication bypass. This vulnerability allows an attacker to gain unauthorized access by circumventing the authentication process.",
"evidence": "osv:DEBIAN-CVE-2026-42010",
"products": [
{
"name": {
"value": "gnutls28",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "3.7.9-2+deb12u7",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "3.7.9-2",
"evidence": "/affected/0/versions"
},
{
"value": "3.7.9-2+deb12u1",
"evidence": "/affected/0/versions"
},
{
"value": "3.7.9-2+deb12u2",
"evidence": "/affected/0/versions"
},
{
"value": "3.7.9-2+deb12u3",
"evidence": "/affected/0/versions"
},
{
"value": "3.7.9-2+deb12u4",
"evidence": "/affected/0/versions"
},
{
"value": "3.7.9-2+deb12u5",
"evidence": "/affected/0/versions"
},
{
"value": "3.7.9-2+deb12u6",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "gnutls28",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "3.8.9-3+deb13u4",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": [
{
"value": "3.8.9-3",
"evidence": "/affected/1/versions"
},
{
"value": "3.8.9-3+deb13u1",
"evidence": "/affected/1/versions"
},
{
"value": "3.8.9-3+deb13u2",
"evidence": "/affected/1/versions"
},
{
"value": "3.8.9-3+deb13u3",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "gnutls28",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "3.8.13-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "3.8.10-1",
"evidence": "/affected/2/versions"
},
{
"value": "3.8.10-2",
"evidence": "/affected/2/versions"
},
{
"value": "3.8.10-3",
"evidence": "/affected/2/versions"
},
{
"value": "3.8.11-1",
"evidence": "/affected/2/versions"
},
{
"value": "3.8.11-2",
"evidence": "/affected/2/versions"
},
{
"value": "3.8.11-3",
"evidence": "/affected/2/versions"
},
{
"value": "3.8.12-1",
"evidence": "/affected/2/versions"
},
{
"value": "3.8.12-2",
"evidence": "/affected/2/versions"
},
{
"value": "3.8.12-3",
"evidence": "/affected/2/versions"
},
{
"value": "3.8.12-4",
"evidence": "/affected/2/versions"
},
{
"value": "3.8.9-3",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "critical",
"structured": {
"id": "DEBIAN-CVE-2026-42010",
"aliases": [
"DEBIAN-CVE-2026-42010"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.7.9-2+deb12u7"
}
]
}
],
"package": {
"name": "gnutls28",
"purl": "pkg:deb/debian/gnutls28?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"3.7.9-2",
"3.7.9-2+deb12u1",
"3.7.9-2+deb12u2",
"3.7.9-2+deb12u3",
"3.7.9-2+deb12u4",
"3.7.9-2+deb12u5",
"3.7.9-2+deb12u6"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42010.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.8.9-3+deb13u4"
}
]
}
],
"package": {
"name": "gnutls28",
"purl": "pkg:deb/debian/gnutls28?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"3.8.9-3",
"3.8.9-3+deb13u1",
"3.8.9-3+deb13u2",
"3.8.9-3+deb13u3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42010.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.8.13-1"
}
]
}
],
"package": {
"name": "gnutls28",
"purl": "pkg:deb/debian/gnutls28?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"3.8.10-1",
"3.8.10-2",
"3.8.10-3",
"3.8.11-1",
"3.8.11-2",
"3.8.11-3",
"3.8.12-1",
"3.8.12-2",
"3.8.12-3",
"3.8.12-4",
"3.8.9-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42010.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-31T09:47:31.418345493Z",
"provider": "osv",
"upstream": [
"CVE-2026-42010"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-42010"
]
},
"related_cves": [
{
"value": "CVE-2026-42010",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 460990,
"published_at": "2026-05-07T12:16:17.977+00:00"
}