VU#369611: ExLlamaV3 contains Denial of Service vulnerability via insufficient bounds checking on kernel dispatch index

Summary

Overview An out-of-bounds (OOB) memory access vulnerability involving unchecked array indexing has been identified in the exllamav3_ext compute unified device architecture ( CUDA ) extension. Successful exploitation can lead to an immediate denial of service or application instability. This vulnerability is tracked as CVE-2026-84286. Description An OOB memory access vulnerability exists in the exllamav3_ext module due to insufficient input validation. When the kernel parameter K is set to 0 in a crafted input, the extension generates a negative array index, resulting in a CUDA illegal memory access.s. The root cause is a missing bounds check in the kernel-table dispatch process. The checkpoint-derived block index ( cbi ) is used to access a fixed 24-entry array without confirming that either K or cbi fall within safe limits. Impact... Related CVEs: CVE-2026-84286.

Why it matters

CERT/CC notes often cover coordinated disclosures, multi-vendor exposure, infrastructure risk, or cases where remediation guidance is still developing.

Operator check

Review the CERT/CC Vulnerability Note and compare the affected vendor and product list against your inventory. Apply vendor fixes or compensating controls for ExLlamaV3 where available.

Sources