Heap Overflow in TLS 1.3 ECH parsing. An integer underflow existed in ECH extension parsing logic when calculating a buffer length, which resulted in writing beyond the bounds of an allocated buffer. Note that in wolfSSL, ECH is off by default, and the ECH standard is still evolving.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3549.json",
"cwe_ids": [
"CWE-122"
],
"cna_assigner": "wolfSSL"
}{
"cpe": "cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*",
"source": [
"AFFECTED_FIELD",
"CPE_RANGE"
],
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "5.9.0"
}
]
}