Scapy before 2.8.0 Uncontrolled Recursion DoS via BER SEQUENCE Decoder
CVE-2026-128238

6.9MEDIUM

Key Information:

Vendor

Secdev

Status
Scapy
Vendor
CVE Published:
13 November 2026

What is CVE-2026-128238?

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.

Affected Version(s)

scapy 0 < 2.8.0

scapy 2.8.0

References

https://github.com/secdev/scapy/security/advisories/GHSA-...
vendor-advisory
https://www.vulncheck.com/advisories/scapy-before-2.8.0-u...
third-party-advisory

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

infycore
.