CVE-2026-128238

Scapy before 2.8.0 Uncontrolled Recursion DoS via BER SEQUENCE Decoder

Published Nov 13, 2026 CVSS 4.0 · 6.9 Medium EPSS n/a KEV · Not listed

Description

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 Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

secdev

scapy

unaffected

Version	Status	Constraints
`0`	affected	< 2.8.0
`2.8.0`	unaffected	—

No data.

No data available yet.

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://github.com/secdev/scapy/security/advisories/GHSA-456h-w4v7-hvpr
https://www.vulncheck.com/advisories/scapy-before-2.8.0-uncontrolled-recursion-dos-via-ber-sequence-decoder

History

Nov 13, 2026 9:45 AM Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		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.
Title		Scapy before 2.8.0 Uncontrolled Recursion DoS via BER SEQUENCE Decoder
First Time appeared		Scapy Scapy scapy
Weaknesses		CWE-674
CPEs		cpe:2.3:a:scapy:scapy::::::::
Vendors & Products		Scapy Scapy scapy
References		https://github.com/secdev/scapy/security/advisories/GHSA-456h-w4v7-hvpr https://www.vulncheck.com/advisories/scapy-before-2.8.0-uncontrolled-recursion-dos-via-ber-sequence-decoder
Metrics		cvssV3_1 `{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}` cvssV4_0 `{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}`