Scapy before 2.8.0 Denial of Service via Quadratic BER OID Decoding
CVE-2026-128237

6.9MEDIUM

Key Information:

Vendor

Secdev

Status
Scapy
Vendor
CVE Published:
13 November 2026

What is CVE-2026-128237?

Scapy before 2.8.0 contains a denial of service vulnerability in BER_num_dec() and BERcodec_OID.do_dec() that allows remote attackers to exhaust CPU by supplying oversized OID arcs. Attackers can send ASN.1/BER data with many base-128 continuation bytes to cause quadratic CPU consumption or an uncaught ValueError crash on Python 3.11+.

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-d...
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

tynus2
.