python-socketio is a Python implementation of the Socket.IO realtime client and server. 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. 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. 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. 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 remote Fedora 43 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2025-3673a159a9 advisory.

    **Release 5.14.2** - 2025-10-15

    - Restore binary message support in message queue setups
    - Fix formatting of client connection error

    ----

    **Release 5.14.1** - 2025-10-02

    - Restore support for `rediss://` URLs, and add support for `valkeys://` as well
    - Add support for Redis connections using unix sockets

    **Release 5.14.0** - 2025-09-30

    - Replace pickle with json in message queue communications
    - Add support for Valkey in the Redis client managers
    - Keep track of which namespaces failed to connect
    - Fixed transport property of the simple clients to be a string as documented
    - SimpleClient.call does not raise `TimeoutError` on timeout
    - Wait for client to end background tasks on disconnect
    - Better error logging for the Redis managers
    - Channel was not properly initialized in several pubsub client managers
    - Add message queue deployment recommendations for security
    - Add missing `async` on session examples for the async server
    - Add SPDX license identifier


Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 / openSUSE 15 host has a package installed that is affected by a vulnerability as referenced in the SUSE-SU-2025:3780-1 advisory.

    - CVE-2025-61765: fixed by using json, rather than pickle for serialization (bsc#1251193)

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 42 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2025-96c38634c7 advisory.

    **Release 5.14.1** - 2025-10-02

    - Restore support for `rediss://` URLs, and add support for `valkeys://` as well
    - Add support for Redis connections using unix sockets

    **Release 5.14.0** - 2025-09-30

    - Replace pickle with json in message queue communications
    - Add support for Valkey in the Redis client managers
    - Keep track of which namespaces failed to connect
    - Fixed transport property of the simple clients to be a string as documented
    - SimpleClient.call does not raise `TimeoutError` on timeout
    - Wait for client to end background tasks on disconnect
    - Better error logging for the Redis managers
    - Channel was not properly initialized in several pubsub client managers
    - Add message queue deployment recommendations for security
    - Add missing `async` on session examples for the async server
    - Add SPDX license identifier


Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - python-socketio is a Python implementation of the Socket.IO realtime client and server. 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. 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. 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. 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. (CVE-2025-61765)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
271453	Fedora 43 : python-socketio (2025-3673a159a9)	Nessus	Fedora Local Security Checks	medium
271430	SUSE SLED15 / SLES15 / openSUSE 15 Security Update : python-python-socketio (SUSE-SU-2025:3780-1)	Nessus	SuSE Local Security Checks	medium
270070	Fedora 42 : python-socketio (2025-96c38634c7)	Nessus	Fedora Local Security Checks	medium
269313	Linux Distros Unpatched Vulnerability : CVE-2025-61765	Nessus	Misc.	medium

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CVE-2025-61765

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