High
wolfssl — security advisory
Out-of-bounds heap read during SM2/SM3 certificate signature verification. When parsing a certificate with an SM3wSM2 signature, the Subject Key Identifier computation reads the trailing 65 bytes of the public key without checking that the key is at least that long. A public key shorter than 65 bytes results in an out-of-bounds heap read, leading to a potential crash (denial of service); there is no out-of-bounds write. Note this only affects builds with SM2 support (--enable-sm2 or --enable-all).
- 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-2026-12340
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:02 UTC · Revision 1
Source evidence
Out-of-bounds heap read during SM2/SM3 certificate signature verification. When parsing a certificate with an SM3wSM2 signature, the Subject Key Identifier computation reads the trailing 65 bytes of the public key without checking that the key is at least that long. A public key shorter than 65 bytes results in an out-of-bounds heap read, leading to a potential crash (denial of service); there is no out-of-bounds write. Note this only affects builds with SM2 support (--enable-sm2 or --enable-all).
osv:UBUNTU-CVE-2026-12340
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": "ea990ba4e390aedf7bc310310ea7575e5bbea4ca780100d4117031da1a60f2d9",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-12340",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-12340",
"summary": "Out-of-bounds heap read during SM2/SM3 certificate signature verification. When parsing a certificate with an SM3wSM2 signature, the Subject Key Identifier computation reads the trailing 65 bytes of the public key without checking that the key is at least that long. A public key shorter than 65 bytes results in an out-of-bounds heap read, leading to a potential crash (denial of service); there is no out-of-bounds write. Note this only affects builds with SM2 support (--enable-sm2 or --enable-all).",
"evidence": "osv:UBUNTU-CVE-2026-12340",
"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": "high",
"structured": {
"id": "UBUNTU-CVE-2026-12340",
"aliases": [
"UBUNTU-CVE-2026-12340"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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-2026-12340.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-2026-12340.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-2026-12340.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-2026-12340.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-2026-12340.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-2026-12340.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-2026-12340.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-2026-12340.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl44",
"binary_version": "5.9.1-0.1"
}
]
}
}
],
"modified": "2026-10-17T12:58:04.914225285Z",
"provider": "osv",
"upstream": [
"CVE-2026-12340"
],
"references": [
"https://ubuntu.com/security/CVE-2026-12340",
"https://www.cve.org/CVERecord?id=CVE-2026-12340",
"https://github.com/wolfSSL/wolfssl/pull/10641",
"https://www.wolfssl.com/docs/security-vulnerabilities/"
]
},
"related_cves": [
{
"value": "CVE-2026-12340",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/1/score"
},
"source_id": "core-osv",
"document_id": 357982,
"published_at": "2026-06-25T20:17:00+00:00"
}