CVE-2026-109311: vLLM before 0.29.0 Heap Overflow DoS via IAMF Audio Transcription Upload

Q: Which deployments are exposed?

vLLM deployments running a version before 0.29.0 are exposed if the /v1/audio/transcriptions endpoint is reachable by an authenticated user and processes uploaded audio through the PyAV/FFmpeg fallback.

Q: What does an attacker need to exploit this issue?

An attacker needs valid authentication and network access to the audio transcription API endpoint. They can submit malformed IAMF containers repeatedly; no user interaction is required.

Q: What is the practical impact of successful exploitation?

Successful exploitation corrupts heap memory in FFmpeg's IAMF parser and crashes the vLLM API process, causing denial of service. The provided data does not indicate confidentiality or integrity impact.

Q: What can be done if upgrading is not immediately possible?

Restrict access to /v1/audio/transcriptions to trusted authenticated users and prevent IAMF audio uploads from reaching the service. File-size checks alone do not mitigate the issue.

Published Oct 12, 2026

Updated

vLLM before 0.29.0 passes uploaded audio to the PyAV/FFmpeg av.open() fallback with only a file-size check, exposing FFmpeg's IAMF parser heap overflow. Authenticated remote attackers can repeatedly upload malformed IAMF containers to /v1/audio/transcriptions, corrupting the heap and crashing the API process.

Affected Software

1 affected component

vllm vllm<0.29.0

Event History

Oct 12, 2026

CVE Published

via MITRE·04:05 PM

Data Sourced

via MITRE·04:05 PM

DescriptionSeverityWeakness

Data Sourced

via NVD·05:17 PM

DescriptionSeverityWeakness

Frequently Asked Questions

Which deployments are exposed?

vLLM deployments running a version before 0.29.0 are exposed if the /v1/audio/transcriptions endpoint is reachable by an authenticated user and processes uploaded audio through the PyAV/FFmpeg fallback.

What does an attacker need to exploit this issue?

An attacker needs valid authentication and network access to the audio transcription API endpoint. They can submit malformed IAMF containers repeatedly; no user interaction is required.

What is the practical impact of successful exploitation?

Successful exploitation corrupts heap memory in FFmpeg's IAMF parser and crashes the vLLM API process, causing denial of service. The provided data does not indicate confidentiality or integrity impact.

What can be done if upgrading is not immediately possible?

Restrict access to /v1/audio/transcriptions to trusted authenticated users and prevent IAMF audio uploads from reaching the service. File-size checks alone do not mitigate the issue.

CVE-2026-109311: vLLM before 0.29.0 Heap Overflow DoS via IAMF Audio Transcription Upload

Affected Software

Event History

Frequently Asked Questions

Which deployments are exposed?

What does an attacker need to exploit this issue?

What is the practical impact of successful exploitation?

What can be done if upgrading is not immediately possible?

Company

Resources

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Frequently Asked Questions

Which deployments are exposed?

What does an attacker need to exploit this issue?

What is the practical impact of successful exploitation?

What can be done if upgrading is not immediately possible?