wolfSSL: out-of-bounds read (DoS) in ALPN parsing due to incomplete validation
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-3547
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 06:03 UTC · Revision 1
Source evidence
wolfSSL: out-of-bounds read (DoS) in ALPN parsing due to incomplete validation
core-osv · Original sourcePublished 19 Mar 2026, 20:20 UTC
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.
osv:CVE-2026-3547
Complete source record
{
"id": "668319e3f4d1871c1fa8e332432852a8fd4a9307f99862604577b7ac66a719bd",
"url": "https://osv.dev/vulnerability/CVE-2026-3547",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "wolfSSL: out-of-bounds read (DoS) in ALPN parsing due to incomplete validation",
"summary": "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.",
"evidence": "osv:CVE-2026-3547",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-3547",
"aliases": [
"CVE-2026-3547"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/wolfssl/wolfssl",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "922d04b3568c6428a9fb905ddee3ef5a68db3108"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "5.9.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"cpe": "cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "5.9.0"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v5.8.4-stable",
"wolfEntropy2d",
"v5.8.2-stable",
"wolfEntropy1",
"v5.8.0-stable",
"v5.7.6-stable",
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"v4.6.0-stable",
"v4.5.0-stable",
"v4.4.0-stable",
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"v3.12.0-stable",
"v3.11.1-tls13-beta",
"v3.11.0-stable",
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"v3.10.2-stable",
"v3.10.0a",
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"v3.9.8",
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"v3.9.6",
"v3.9.1",
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"v3.7.3",
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"v3.7.0",
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"v2.0rc2",
"v2.0rc1",
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],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-3547.json"
}
}
],
"modified": "2026-10-28T02:30:26.508891136Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3547.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-3547",
"https://github.com/wolfSSL/wolfssl/pull/9859"
],
"provider_metadata": {
"cwe_ids": [
"CWE-125"
],
"cna_assigner": "wolfSSL",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3547.json"
}
},
"related_cves": [
{
"value": "CVE-2026-3547",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 492918,
"published_at": "2026-03-19T20:20:42.608+00:00"
}