id: PYSEC-2026-3042
published: "2026-07-13T15:46:24.787391Z"
modified: "2026-07-13T16:06:05.778623Z"
aliases:
- CVE-2026-48804
- GHSA-5w7q-77mv-v69f
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."
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
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
severity:
- type: CVSS_V3
  score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H