CVE-2026-39804

Что произошло

Allocation of Resources Without Limits or Throttling vulnerability in mtrudel bandit allows unauthenticated remote denial of service via memory exhaustion when WebSocket permessage-deflate compression is enabled. 'Elixir.Bandit.WebSocket.PerMessageDeflate':inflate/2 in lib/bandit/websocket/permessage_deflate.ex calls :zlib.inflate/2 with no output-size cap, then materializes the entire decompressed payload as a single binary via IO.iodata_to_binary/1. The websocket_options.max_frame_size option only bounds the on-the-wire (compressed) frame size, not the decompressed output. A high-ratio compressed frame (e.g. uniform data at ~1024:1 ratio) can stay well under any wire-size limit while forcing GiB-scale heap allocations in the connection process before any application code runs. An unauthenticated attacker who can open a WebSocket connection can send a single such frame to exhaust the BEAM node's memory and trigger an OOM kill. This vulnerability requires both Bandit's server-level websocket_options.compress and the per-upgrade compress: true option passed to WebSockAdapter.upgrade/4 to be enabled. Stock Phoenix and LiveView applications are not affected as they default to compress: false. This issue affects bandit: from 0.5.9 before 1.11.0.

Что делать

dpkg-query -W -f='${Package}	${Version}\n'

rpm -qa --qf '%{NAME}\t%{VERSION}-%{RELEASE}\n'

Get-HotFix | Select-Object HotFixID, InstalledOn

Продукты и затронутые версии

{
  "status": "affected",
  "version": "0.5.9",
  "lessThan": "1.11.0",
  "versionType": "semver"
}

cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*

{
  "status": "affected",
  "version": "da4027cff7d2b80319e76fe7a32f84beceec490a",
  "lessThan": "8156921a51e684a951221da7bc30a70a022f722e",
  "versionType": "git"
}

cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*

CVSS: оценки и векторы

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Источники и ссылки

{
  "cwes": [
    "cve",
    "nvd"
  ],
  "epss": {
    "source": "epss",
    "received_at": "2026-11-02T21:12:30.172149+00:00"
  },
  "title": {
    "source": "cve",
    "received_at": "2026-10-28T19:17:01.109901+00:00"
  },
  "scores": [
    "cve",
    "nvd"
  ],
  "status": {
    "source": "cve",
    "received_at": "2026-10-28T19:17:01.109901+00:00"
  },
  "affected": [
    "cve"
  ],
  "published": {
    "source": "cve",
    "received_at": "2026-10-28T19:17:01.109901+00:00"
  },
  "solutions": [],
  "percentile": {
    "source": "epss",
    "received_at": "2026-11-02T21:12:30.172149+00:00"
  },
  "references": [
    "cve",
    "nvd"
  ],
  "description": {
    "source": "cve",
    "received_at": "2026-10-28T19:17:01.109901+00:00"
  },
  "workarounds": [
    "cve"
  ],
  "configurations": []
}

Хронология записи

1. Данные обновлены03.11.2026, 00:12
2. Данные обновлены02.11.2026, 00:11
3. Данные обновлены31.10.2026, 11:58
4. Появилась ссылка на PoC28.10.2026, 22:17
5. Данные обновлены28.10.2026, 18:06
6. Опубликована28.10.2026, 15:13

Личная заметка и статус

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