CVE-2026-5497: Unbounded Frame Count in video/jpeg Base64 Data URL Processing Leads to OOM DoS in vllm-project/vllm
vLLM versions 0.8.0 and later are vulnerable to an Out-of-Memory (OOM) Denial of Service (DoS) attack due to unbounded frame count processing in the VideoMediaIO.loadbase64() method. When processing video/jpeg data URLs, the method splits the base64 data string on commas to extract individual JPEG frames without enforcing a frame count limit. An attacker can exploit this by crafting a single API request containing thousands of comma-separated base64-encoded JPEG frames in a data URL, causing the server to decode all frames into memory and crash due to excessive memory consumption. This vulnerability is reachable via the OpenAI-compatible chat completions API and does not require authentication.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
In vllm-project/vllm, modify the `VideoMediaIO.load_base64()` logic that processes `video/jpeg` data URLs to enforce a maximum frame count when splitting the base64 string on commas, instead of processing an unbounded number of frames (vulnerable in vLLM versions 0.8.0 and later).
vllm-project/vllm video/jpeg data URL frame count limit (enforce maximum frames) = max_frames (set a strict upper bound) - Compensating control
Add an external rate limit for the OpenAI-compatible chat completions API endpoint to reduce the impact of unauthenticated abuse delivering extremely large video/jpeg data URLs with thousands of base64 frames.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-5497?
CVE-2026-5497 has a severity rating of high with a score of 7.5.
How do I fix CVE-2026-5497?
To mitigate CVE-2026-5497, update to a patched version of vLLM that addresses the unbounded frame count in the VideoMediaIO.load_base64() method.
What kind of attack does CVE-2026-5497 facilitate?
CVE-2026-5497 can facilitate an Out-of-Memory (OOM) Denial of Service (DoS) attack.
Which versions of vLLM are affected by CVE-2026-5497?
vLLM versions 0.8.0 and later are affected by CVE-2026-5497.
What does the term 'unbounded frame count' mean in relation to CVE-2026-5497?
In the context of CVE-2026-5497, 'unbounded frame count' refers to the method's inability to limit the number of frames it processes, potentially leading to excessive memory usage.