Critical
wolfssl — security advisory
Two buffer overflow vulnerabilities existed in the wolfSSL CRL parser when parsing CRL numbers: a heap-based buffer overflow could occur when improperly storing the CRL number as a hexadecimal string, and a stack-based overflow for sufficiently sized CRL numbers. With appropriately crafted CRLs, either of these out of bound writes could be triggered. Note this only affects builds that specifically enable CRL support, and the user would need to load a CRL from an untrusted source.
- Products
- wolfssl
- Affected versions
- 3.10.2+dfsg-2, 3.12.0+dfsg-1, 3.12.2+dfsg-1, 3.13.0+dfsg-1, 3.4.8+dfsg-1, 4.1.0+dfsg-2, 4.2.0+dfsg-1, 4.2.0+dfsg-2, 4.2.0+dfsg-3, 4.3.0+dfsg-2, 4.6.0-3, 5.0.0-1, 5.1.1-1, 5.2.0-1, 5.2.0-2, 5.5.4-2, 5.5.4-2.1, 5.6.4-2, 5.6.6-1.2, 5.6.6-1.3, 5.6.6-1.3build1, 5.7.2-0.1, 5.8.2-1.2, 5.8.4-1, 5.9.1-0.1, 5.9.2-1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-3548
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:02 UTC · Revision 1
Source evidence
Two buffer overflow vulnerabilities existed in the wolfSSL CRL parser when parsing CRL numbers: a heap-based buffer overflow could occur when improperly storing the CRL number as a hexadecimal string, and a stack-based overflow for sufficiently sized CRL numbers. With appropriately crafted CRLs, either of these out of bound writes could be triggered. Note this only affects builds that specifically enable CRL support, and the user would need to load a CRL from an untrusted source.
osv:UBUNTU-CVE-2026-3548
wolfssl
Fixed versions: Not specified
wolfssl
Fixed versions: Not specified
wolfssl
Fixed versions: Not specified
wolfssl
Fixed versions: Not specified
wolfssl
Fixed versions: Not specified
wolfssl
Fixed versions: Not specified
wolfssl
Fixed versions: Not specified
wolfssl
Fixed versions: Not specified
Complete source record
{
"id": "676fffe659eef6b2c858d60d4f8040adeb1f410bb85447b5b4cc1bfb9dd280ef",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-3548",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-3548",
"summary": "Two buffer overflow vulnerabilities existed in the wolfSSL CRL parser when parsing CRL numbers: a heap-based buffer overflow could occur when improperly storing the CRL number as a hexadecimal string, and a stack-based overflow for sufficiently sized CRL numbers. With appropriately crafted CRLs, either of these out of bound writes could be triggered. Note this only affects builds that specifically enable CRL support, and the user would need to load a CRL from an untrusted source.",
"evidence": "osv:UBUNTU-CVE-2026-3548",
"products": [
{
"name": {
"value": "wolfssl",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.4.8+dfsg-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "wolfssl",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.10.2+dfsg-2",
"evidence": "/affected/1/versions"
},
{
"value": "3.12.0+dfsg-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.12.2+dfsg-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.13.0+dfsg-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "wolfssl",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.1.0+dfsg-2",
"evidence": "/affected/2/versions"
},
{
"value": "4.2.0+dfsg-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.2.0+dfsg-2",
"evidence": "/affected/2/versions"
},
{
"value": "4.2.0+dfsg-3",
"evidence": "/affected/2/versions"
},
{
"value": "4.3.0+dfsg-2",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "wolfssl",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.6.0-3",
"evidence": "/affected/3/versions"
},
{
"value": "5.0.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "5.1.1-1",
"evidence": "/affected/3/versions"
},
{
"value": "5.2.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "5.2.0-2",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "wolfssl",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "5.5.4-2",
"evidence": "/affected/4/versions"
},
{
"value": "5.5.4-2.1",
"evidence": "/affected/4/versions"
},
{
"value": "5.6.4-2",
"evidence": "/affected/4/versions"
},
{
"value": "5.6.6-1.2",
"evidence": "/affected/4/versions"
},
{
"value": "5.6.6-1.3",
"evidence": "/affected/4/versions"
},
{
"value": "5.6.6-1.3build1",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "wolfssl",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "5.7.2-0.1",
"evidence": "/affected/5/versions"
}
]
},
{
"name": {
"value": "wolfssl",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "5.9.1-0.1",
"evidence": "/affected/6/versions"
},
{
"value": "5.9.2-1",
"evidence": "/affected/6/versions"
}
]
},
{
"name": {
"value": "wolfssl",
"evidence": "/affected/7/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "5.7.2-0.1",
"evidence": "/affected/7/versions"
},
{
"value": "5.8.2-1.2",
"evidence": "/affected/7/versions"
},
{
"value": "5.8.4-1",
"evidence": "/affected/7/versions"
},
{
"value": "5.9.1-0.1",
"evidence": "/affected/7/versions"
}
]
}
],
"severity": "critical",
"structured": {
"id": "UBUNTU-CVE-2026-3548",
"aliases": [
"UBUNTU-CVE-2026-3548"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl?arch=source&distro=xenial",
"ecosystem": "Ubuntu:16.04:LTS"
},
"versions": [
"3.4.8+dfsg-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3548.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcyassl5",
"binary_version": "3.4.8+dfsg-1"
},
{
"binary_name": "libwolfssl0",
"binary_version": "3.4.8+dfsg-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl?arch=source&distro=bionic",
"ecosystem": "Ubuntu:18.04:LTS"
},
"versions": [
"3.10.2+dfsg-2",
"3.12.0+dfsg-1",
"3.12.2+dfsg-1",
"3.13.0+dfsg-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3548.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl15",
"binary_version": "3.13.0+dfsg-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"4.1.0+dfsg-2",
"4.2.0+dfsg-1",
"4.2.0+dfsg-2",
"4.2.0+dfsg-3",
"4.3.0+dfsg-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3548.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl24",
"binary_version": "4.3.0+dfsg-2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"4.6.0-3",
"5.0.0-1",
"5.1.1-1",
"5.2.0-1",
"5.2.0-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3548.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl32",
"binary_version": "5.2.0-2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"5.5.4-2",
"5.5.4-2.1",
"5.6.4-2",
"5.6.6-1.2",
"5.6.6-1.3",
"5.6.6-1.3build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3548.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl42t64",
"binary_version": "5.6.6-1.3build1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl?arch=source&distro=questing",
"ecosystem": "Ubuntu:25.10"
},
"versions": [
"5.7.2-0.1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3548.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl42t64",
"binary_version": "5.7.2-0.1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"5.9.1-0.1",
"5.9.2-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3548.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl45",
"binary_version": "5.9.2-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"5.7.2-0.1",
"5.8.2-1.2",
"5.8.4-1",
"5.9.1-0.1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-3548.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl44",
"binary_version": "5.9.1-0.1"
}
]
}
}
],
"modified": "2026-10-17T13:00:02.905461932Z",
"provider": "osv",
"upstream": [
"CVE-2026-3548"
],
"references": [
"https://ubuntu.com/security/CVE-2026-3548",
"https://www.cve.org/CVERecord?id=CVE-2026-3548",
"https://github.com/wolfSSL/wolfssl/pull/9628/",
"https://github.com/wolfSSL/wolfssl/pull/9873/"
]
},
"related_cves": [
{
"value": "CVE-2026-3548",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/1/score"
},
"source_id": "core-osv",
"document_id": 360190,
"published_at": "2026-03-19T18:16:00+00:00"
}