{"id":"PYSEC-2026-3042","summary":"python-socketio: Binary attachment accumulation can cause denial of service","details":"### Impact\nThe python-socketio server stores binary `EVENT` and `ACK` messages in memory while it waits to receive their binary attachments. Once all the attachments are received, these messages are then processed. An attacker can submit a binary message and intentionally omit sending one or more of its attachments to cause the message along with the partial list of received attachments to stay in memory for a long time.\n\n### Patches\nVersion 5.16.2 takes the following measures to address this issue:\n- Binary packets are only accepted from authenticated clients.\n- When a client disconnects, the server checks if there is a partial binary message being held for the client and deletes it.","aliases":["CVE-2026-48804","GHSA-5w7q-77mv-v69f"],"modified":"2026-07-13T16:33:29.305219409Z","published":"2026-07-13T15:46:24.787391Z","references":[{"type":"WEB","url":"https://github.com/miguelgrinberg/python-socketio/security/advisories/GHSA-5w7q-77mv-v69f"},{"type":"PACKAGE","url":"https://github.com/miguelgrinberg/python-socketio"},{"type":"PACKAGE","url":"https://pypi.org/project/python-socketio"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-5w7q-77mv-v69f"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48804"}],"affected":[{"package":{"name":"python-socketio","ecosystem":"PyPI","purl":"pkg:pypi/python-socketio"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.16.2"}]}],"versions":["0.1.0","0.2.0","0.3.0","0.4.0","0.4.1","0.4.2","0.5.0","0.5.1","0.5.2","0.6.0","0.6.1","0.7.0","0.8.0","0.8.1","0.8.2","0.9.0","0.9.1","0.9.2","1.0","1.1","1.2","1.3","1.4","1.4.1","1.4.2","1.4.3","1.4.4","1.5.0","1.5.1","1.6.0","1.6.1","1.6.2","1.6.3","1.7.0","1.7.1","1.7.2","1.7.3","1.7.4","1.7.5","1.7.6","1.7.7","1.8.0","1.8.1","1.8.2","1.8.3","1.8.4","1.9.0","2.0.0","2.1.0","2.1.1","2.1.2","3.0.0","3.0.1","3.1.0","3.1.1","3.1.2","4.0.0","4.0.1","4.0.2","4.0.3","4.1.0","4.2.0","4.2.1","4.3.0","4.3.1","4.4.0","4.5.0","4.5.1","4.6.0","4.6.1","5.0.0","5.0.1","5.0.2","5.0.3","5.0.4","5.1.0","5.10.0","5.11.0","5.11.1","5.11.2","5.11.3","5.11.4","5.12.0","5.12.1","5.13.0","5.14.0","5.14.1","5.14.2","5.14.3","5.15.0","5.15.1","5.16.0","5.16.1","5.2.0","5.2.1","5.3.0","5.4.0","5.4.1","5.5.0","5.5.1","5.5.2","5.6.0","5.7.0","5.7.1","5.7.2","5.8.0","5.9.0"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/python-socketio/PYSEC-2026-3042.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}