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PYSEC-2026-1854
python-socketioSummary
A remote code execution vulnerability in python-socketio versions prior to 5.14.0 allows attackers to execute arbitrary Python code through malicious pickle deserialization in multi-server deployments on which the attacker previously gained access to the message queue that the servers use for internal communications.
Details
When Socket.IO servers are configured to use a message queue backend such as Redis for inter-server communication, messages sent between the servers are encoded using the pickle Python module. When a server receives one of these messages through the message queue, it assumes it is trusted and immediately deserializes it.
The vulnerability stems from deserialization of messages using Python's pickle.loads() function. Having previously obtained access to the message queue, the attacker can send a python-socketio server a crafted pickle payload that executes arbitrary code during deserialization via Python's __reduce__ method.
Impact
This vulnerability only affects deployments with a compromised message queue. The attack can lead to the attacker executing random code in the context of, and with the privileges of a Socket.IO server process.
Single-server systems that do not use a message queue, and multi-server systems with a secure message queue are not vulnerable.
Remediation
In addition to making sure standard security practices are followed in the deployment of the message queue, users of the python-socketio package can upgrade to version 5.14.0 or newer, which remove the pickle module and use the much safer JSON encoding for inter-server messaging.
The vulnerability can be exploited over a local network, such as Wi-Fi. It is easy for an attacker to exploit this vulnerability. An attacker needs high-level or administrative privileges. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a low impact on the availability of the system.
Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.
The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
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