Scapy before 2.8.0 contains an uncontrolled recursion vulnerability in the BER/ASN.1 decoder in scapy/asn1/ber.py that allows unauthenticated remote attackers to crash parsing applications. Attackers can send a single 833-byte packet with 250 nested ASN.1 SEQUENCE structures to trigger an unhandled RecursionError, terminating TLS, SNMP, X.509, or LDAP parsers even with safe=True.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-674"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/128xxx/CVE-2026-128238.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "2.8.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}