CVE-2026-109225: SGLang through 0.5.21 Memory Exhaustion DoS via /v1/audio/transcriptions Upload
SGLang through 0.5.21 contains an unbounded memory allocation vulnerability that allows unauthenticated remote attackers to exhaust memory by uploading oversized files to /v1/audio/transcriptions. Attackers can send concurrent large multipart uploads, which are fully read into memory before validation, to crash the HTTP/tokenizer worker and deny service.
Affected Software
Event History
Frequently Asked Questions
Who is exposed to this issue?
Any SGLang deployment through 0.5.21 that exposes the /v1/audio/transcriptions endpoint to remote clients is exposed. No authentication is required to submit the malicious uploads.
What does an attacker need to do to cause denial of service?
An attacker can send oversized multipart uploads to /v1/audio/transcriptions, including concurrent large uploads. The files are fully read into memory before validation, allowing memory exhaustion that can crash the HTTP/tokenizer worker.
Are confidentiality or integrity affected?
The provided severity vector indicates no confidentiality or integrity impact. The documented impact is availability loss through exhaustion of process memory.