{"id":"CVE-2025-61765","aliases":["GHSA-g8c6-8fjj-2r4m","PYSEC-2026-1854"],"url":"https://o3.security/vulnerability/CVE-2025-61765","summary":"python-socketio vulnerable to arbitrary Python code execution (RCE) through malicious pickle deserialization in certain multi-server deployments","details":"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.","published":"2025-10-06T16:04:22.559Z","modified":"2026-07-15T01:49:10.002995777Z","cvss":{"score":6.4,"severity":"MEDIUM","vector":"CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"python-socketio","fixedVersion":"5.14.0"}],"fix":{"url":"https://github.com/miguelgrinberg/python-socketio/commit/53f6be094257ed81476b0e212c8cddd6d06ca39a","label":"miguelgrinberg/python-socketio@53f6be0"},"references":[{"type":"WEB","url":"https://www.bluerock.io/post/cve-2025-61765-bluerock-discovers-critical-rce-in-socket-io-ecosystem"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/61xxx/CVE-2025-61765.json"},{"type":"ADVISORY","url":"https://github.com/miguelgrinberg/python-socketio/security/advisories/GHSA-g8c6-8fjj-2r4m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-61765"},{"type":"FIX","url":"https://github.com/miguelgrinberg/python-socketio/commit/53f6be094257ed81476b0e212c8cddd6d06ca39a"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-15T01:49:10.002995777Z"}}