UBUNTU-CVE-2026-3547 (CVE-2026-3547)
Vulnerability from osv_ubuntu – Published: 2026-03-19 21:17 – Updated: 2026-05-20 15:24 – Source website
VLAI
Details
Out-of-bounds read in ALPN parsing due to incomplete validation. wolfSSL 5.8.4 and earlier contained an out-of-bounds read in ALPN handling when built with ALPN enabled (HAVE_ALPN / --enable-alpn). A crafted ALPN protocol list could trigger an out-of-bounds read, leading to a potential process crash (denial of service). Note that ALPN is disabled by default, but is enabled for these 3rd party compatibility features: enable-apachehttpd, enable-bind, enable-curl, enable-haproxy, enable-hitch, enable-lighty, enable-jni, enable-nginx, enable-quic.
Severity
7.5 (High)
N/A (UNKNOWN)
References
{
"affected": [
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcyassl5",
"binary_version": "3.4.8+dfsg-1"
},
{
"binary_name": "libwolfssl0",
"binary_version": "3.4.8+dfsg-1"
}
]
},
"package": {
"ecosystem": "Ubuntu:16.04:LTS",
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl@3.4.8+dfsg-1?arch=source\u0026distro=xenial"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"3.4.8+dfsg-1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl15",
"binary_version": "3.13.0+dfsg-1"
}
]
},
"package": {
"ecosystem": "Ubuntu:18.04:LTS",
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl@3.13.0+dfsg-1?arch=source\u0026distro=bionic"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"3.10.2+dfsg-2",
"3.12.0+dfsg-1",
"3.12.2+dfsg-1",
"3.13.0+dfsg-1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl24",
"binary_version": "4.3.0+dfsg-2"
}
]
},
"package": {
"ecosystem": "Ubuntu:20.04:LTS",
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl@4.3.0+dfsg-2?arch=source\u0026distro=focal"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"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"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl32",
"binary_version": "5.2.0-2"
}
]
},
"package": {
"ecosystem": "Ubuntu:22.04:LTS",
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl@5.2.0-2?arch=source\u0026distro=jammy"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.6.0-3",
"5.0.0-1",
"5.1.1-1",
"5.2.0-1",
"5.2.0-2"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl42t64",
"binary_version": "5.6.6-1.3build1"
}
]
},
"package": {
"ecosystem": "Ubuntu:24.04:LTS",
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl@5.6.6-1.3build1?arch=source\u0026distro=noble"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"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"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl42t64",
"binary_version": "5.7.2-0.1"
}
]
},
"package": {
"ecosystem": "Ubuntu:25.10",
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl@5.7.2-0.1?arch=source\u0026distro=questing"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"5.7.2-0.1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libwolfssl44",
"binary_version": "5.9.1-0.1"
}
]
},
"package": {
"ecosystem": "Ubuntu:26.04:LTS",
"name": "wolfssl",
"purl": "pkg:deb/ubuntu/wolfssl@5.9.1-0.1?arch=source\u0026distro=resolute"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"5.7.2-0.1",
"5.8.2-1.2",
"5.8.4-1",
"5.9.1-0.1"
]
}
],
"aliases": [],
"details": "Out-of-bounds read in ALPN parsing due to incomplete validation. wolfSSL 5.8.4 and earlier contained an out-of-bounds read in ALPN handling when built with ALPN enabled (HAVE_ALPN / --enable-alpn). A crafted ALPN protocol list could trigger an out-of-bounds read, leading to a potential process crash (denial of service). Note that ALPN is disabled by default, but is enabled for these 3rd party compatibility features: enable-apachehttpd, enable-bind, enable-curl, enable-haproxy, enable-hitch, enable-lighty, enable-jni, enable-nginx, enable-quic.",
"id": "UBUNTU-CVE-2026-3547",
"modified": "2026-05-20T15:24:29Z",
"published": "2026-03-19T21:17:00Z",
"references": [
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-3547"
},
{
"type": "REPORT",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-3547"
},
{
"type": "REPORT",
"url": "https://github.com/wolfSSL/wolfssl/pull/9859"
},
{
"type": "REPORT",
"url": "https://github.com/wolfSSL/wolfssl/pull/9860"
}
],
"related": [],
"schema_version": "1.7.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"upstream": [
"CVE-2026-3547"
]
}
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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