CVE-2026-109311 vllm-project CVE debrief

Who should care

Defenders responsible for systems using vLLM versions before 0.29.0, especially those with internet-facing API processes, should assess potential exposure and impact. They should verify vLLM version, review compensating controls, and consider upgrading to version 0.29.0 or later. Additionally, defenders should monitor API process for crashes or anomalies and review relevant monitoring, detection, and logs for exposed assets that need extra review.

Why it matters

This vulnerability allows authenticated remote attackers to crash the vLLM API process by uploading malformed IAMF containers, affecting vLLM versions before 0.29.0. Defenders should verify exposure, assess impact, and consider upgrading to version 0.29.0 or later.

• Potential API process crashes due to heap overflow
• Denial-of-service (DoS) attacks via malformed IAMF containers
• Need for verification of vLLM version and exposure
• Potential for compensating controls to limit API access

Technical summary

The vLLM library before version 0.29.0 is vulnerable to a heap overflow denial-of-service (DoS) attack via the IAMF audio transcription upload feature. Authenticated remote attackers can exploit this by uploading malformed IAMF containers to the /v1/audio/transcriptions endpoint, which can corrupt the heap and crash the API process. The vulnerability is due to insufficient validation of uploaded audio files, allowing attackers to exploit the IAMF parser in FFmpeg. Defenders should prioritize verifying exposure and assessing potential impact on systems using vLLM versions before 0.29.0, especially those with internet-facing API processes.

Defensive priority

Defenders should prioritize verifying exposure and assessing potential impact on systems using vLLM versions before 0.29.0, especially those with internet-facing API processes.

Recommended defensive actions

• Verify vLLM version and assess exposure
• Implement compensating controls to limit API access
• Monitor API process for crashes or anomalies
• Consider upgrading to vLLM version 0.29.0 or later
• Review relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the vulnerability, including its description, affected versions, and references to vendor advisories. The vulnerability has been publicly disclosed and affects vLLM versions before 0.29.0. There are no known exploits in the wild, but defenders should verify exposure and assess potential impact. The source item provides additional context on the vulnerability, including its potential impact on systems using vLLM.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.