Medium

Scapy Session Loading Vulnerable to Arbitrary Code Execution via Untrusted Pickle Deserialization

Disclosed: 22.10.2025
Updated: 11.10.2026 12:19

Summary

An unsafe deserialization vulnerability in Scapy <v2.7.0 allows attackers to execute arbitrary code when a malicious session file is locally loaded via the -s option. This requires convincing a user to manually load a malicious session file.

Details

Scapy’s interactive shell supports session loading using gzip-compressed pickle files:

bash

./run_scapy -s <session_file.pkl.gz>

Internally, this triggers:

python

# main.py
SESSION = pickle.load(gzip.open(session_name, "rb"))

Since no validation or restriction is performed on the deserialized object, any code embedded via __reduce__() will be executed immediately. This makes it trivial for an attacker to drop a malicious .pkl.gz in a shared folder and have it executed by unsuspecting users.

The vulnerability exists in the load_session function, which deserializes data using pickle.load() on .pkl.gz files provided via the -s CLI flag or programmatically through conf.session.

Affected lines in source code: https://github.com/secdev/scapy/blob/master/scapy/main.py#L569-L572

python

try:
    s = pickle.load(gzip.open(fname, "rb"))
except IOError:
    try:
        s = pickle.load(open(fname, "rb"))

Impact

This is a classic deserialization vulnerability which leads to Code Execution (CE) when untrusted data is deserialized.

Any user who can trick another user into loading a crafted .pkl.gz session file (e.g. via -s option) can execute arbitrary Python code.

Vulnerability type: Insecure deserialization (Python pickle)
CWE: CWE-502: Deserialization of Untrusted Data
CVSS v4.0 Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 5.4 (Medium)
Impact: Arbitrary Code Execution
Attack vector: Local or supply chain (malicious .pkl.gz)
Affected users: Any user who loads session files (even interactively)
Affected version: Scapy v2.6.1

Mitigations

Do not use 'sessions' (the -s option when launching Scapy).
Use the Scapy 2.7.0+ where the session mechanism has been removed.

Affected software

Click a technology to see all vulnerabilities affecting it.

Platform	Package	Vulnerable versions	Fixed in
Python (PyPI)	scapy	<= 2.6.1	no fix

References

CVSS score -

CVSS vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Weakness (CWE): CWE-502
Platform: Python (PyPI)
Package: scapy
Disclosed: 22.10.2025
Updated: 11.10.2026 12:19

Sources and licenses

OSV / GitHub Advisory Database - GHSA-cq46-m9x9-j8w2 - CC BY 4.0

Vulnerability history: scapy

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

Total entries: 2
First → latest: 07.2019 10.2025
Without a fix: 1
Exploited in attacks: 0

Severity breakdown

High 1
Medium 1

Disclosures per year

2019: 1
2020: 0
2021: 0
2022: 0
2023: 0
2024: 0
2025: 1
2026: 0

22.10.2025

Scapy Session Loading Vulnerable to Arbitrary Code Execution via Untrusted Pickle Deserialization this entry

Medium ghsa-cq46-m9x9-j8w2 <= 2.6.1 no fix
19.07.2019

Infinite Loop in scapy

High · 7.5 CVE-2019-1010142 >= 2.4-rc1, < 2.4.1 2.4.1

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