id: PYSEC-2026-3404
published: "2026-07-13T15:46:18.784318Z"
modified: "2026-07-13T16:07:25.936956Z"
aliases:
- CVE-2026-54233
- GHSA-6pr9-rp53-2pmc
summary: "vLLM: OOM Denial of Service via Audio Decompression Bomb"
details: "### Summary\nvLLM's `/v1/audio/transcriptions` endpoint limits compressed upload size but not decoded PCM output. A 25MB OPUS file expands to ~14.9GB of float32 PCM at decode time. Tested on vLLM v0.19.0.\n\n### Details\n`SpeechToTextProcessor` rejects uploads over `VLLM_MAX_AUDIO_CLIP_FILESIZE_MB` (default 25MB) based on compressed byte length, but the audio decoder in `audio.py` accumulates all decoded frames into memory with no size limit before returning:\n\n```python\n# speech_to_text.py L184-189\nif len(audio_data) / 1024 ** 2 > self.max_audio_filesize_mb:\n    raise VLLMValidationError(...)\ny, sr = load_audio(buf, sr=self.asr_config.sample_rate)  # decoded size unchecked\n\n# audio.py L77-107\nchunks: list[npt.NDArray] = []\nfor frame in container.decode(stream):\n    chunks.append(frame.to_ndarray())\naudio = np.concatenate(chunks, axis=-1).astype(np.float32)  # single contiguous allocation\n```\n\nA 25MB OPUS file at 6kbps encodes ~8.7 hours of audio. Decoding produces ~5.7GB of float32 PCM (232x amplification), and `np.concatenate` then allocates a second contiguous array, bringing peak RSS to ~14.9GB from a single request. `SpeechToTextConfig.max_audio_clip_s` (default 30s) applies only after the full decode and does not prevent the allocation.\n\n### Impact\nAn unauthenticated attacker can exhaust server memory with a small number of concurrent requests, each a valid upload within the documented size limit. Severity was assessed with reference to prior OOM vulnerability reports in vLLM.\n\n### Fix\n\nA fix for this vulnerability was merged here: https://github.com/vllm-project/vllm/pull/44970"
affected:
- package:
    name: vllm
    ecosystem: PyPI
    purl: pkg:pypi/vllm
  ranges:
  - type: ECOSYSTEM
    events:
    - introduced: "0"
    - last_affected: 0.23.0
  versions:
  - 0.0.1
  - 0.1.0
  - 0.1.1
  - 0.1.2
  - 0.1.3
  - 0.1.4
  - 0.1.5
  - 0.1.6
  - 0.1.7
  - 0.10.0
  - 0.10.1
  - 0.10.1.1
  - 0.10.2
  - 0.11.0
  - 0.11.1
  - 0.11.2
  - 0.12.0
  - 0.13.0
  - 0.14.0
  - 0.14.1
  - 0.15.0
  - 0.15.1
  - 0.16.0
  - 0.17.0
  - 0.17.1
  - 0.18.0
  - 0.18.1
  - 0.19.0
  - 0.19.1
  - 0.2.0
  - 0.2.1
  - 0.2.1.post1
  - 0.2.2
  - 0.2.3
  - 0.2.4
  - 0.2.5
  - 0.2.6
  - 0.2.7
  - 0.20.0
  - 0.20.1
  - 0.20.2
  - 0.21.0
  - 0.22.0
  - 0.22.1
  - 0.23.0
  - 0.3.0
  - 0.3.1
  - 0.3.2
  - 0.3.3
  - 0.4.0
  - 0.4.0.post1
  - 0.4.1
  - 0.4.2
  - 0.4.3
  - 0.5.0
  - 0.5.0.post1
  - 0.5.1
  - 0.5.2
  - 0.5.3
  - 0.5.3.post1
  - 0.5.4
  - 0.5.5
  - 0.6.0
  - 0.6.1
  - 0.6.1.post1
  - 0.6.1.post2
  - 0.6.2
  - 0.6.3
  - 0.6.3.post1
  - 0.6.4
  - 0.6.4.post1
  - 0.6.5
  - 0.6.6
  - 0.6.6.post1
  - 0.7.0
  - 0.7.1
  - 0.7.2
  - 0.7.3
  - 0.8.0
  - 0.8.1
  - 0.8.2
  - 0.8.3
  - 0.8.4
  - 0.8.5
  - 0.8.5.post1
  - 0.9.0
  - 0.9.0.1
  - 0.9.1
  - 0.9.2
references:
- type: WEB
  url: https://github.com/vllm-project/vllm/security/advisories/GHSA-6pr9-rp53-2pmc
- type: WEB
  url: https://github.com/vllm-project/vllm/pull/44970
- type: WEB
  url: https://github.com/vllm-project/vllm/commit/1b1359c33269446f13c05da9a90c25174cbea590
- type: PACKAGE
  url: https://github.com/vllm-project/vllm
- type: WEB
  url: https://github.com/vllm-project/vllm/releases/tag/v0.23.1rc0
- type: PACKAGE
  url: https://pypi.org/project/vllm
- type: ADVISORY
  url: https://github.com/advisories/GHSA-6pr9-rp53-2pmc
- type: ADVISORY
  url: https://nvd.nist.gov/vuln/detail/CVE-2026-54233
severity:
- type: CVSS_V3
  score: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H