{"document":{"acknowledgments":[{"urls":["https://kb.cert.org/vuls/id/369611#acknowledgements"]}],"category":"CERT/CC Vulnerability Note","csaf_version":"2.0","notes":[{"category":"summary","text":"### Overview\r\nAn 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.\r\n\r\n### Description\r\nAn OOB memory access vulnerability exists in the `exllamav3_ext` module due to insufficient input validation.\r\n\r\nWhen 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.\r\n\r\n### Impact\r\nPrimary impacts include Denial of Service (DoS) through process crashes and potential unstable execution states within applications utilizing the library.\r\n\r\n### Solution\r\nThe vendor has addressed this vulnerability in the main repository. Users are advised to update their installations or apply the fix from the merged pull request: https://github.com/turboderp-org/exllamav3/pull/310. \r\n\r\n### Supply chain\r\nDownstream projects utilizing this library are indirectly exposed to this vulnerability. According to the `ExLlamaV3` Dependency Graph, there are 49 total dependencies currently tracking this repository. Notable downstream projects directly affected by this supply chain link include: `UnstableLlama` / `ezexl3` and `Ednaordinary` / `MawDiscord`\r\nDevelopers and maintainers of these dependent repositories are strongly encouraged to rebuild their packages against the patched version of `exllamav3_ext`.\r\n\r\n### Acknowledgements\r\nThe CERT Coordination Center (CERT/CC) thanks Nathan Keys (professor-moody) for discovering and responsibly reporting this vulnerability.\r\nThis AI-assisted vulnerability note was prepared by Laurie Tyzenhaus.","title":"Summary"},{"category":"legal_disclaimer","text":"THIS DOCUMENT IS PROVIDED ON AN 'AS IS' BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. ","title":"Legal Disclaimer"},{"category":"other","text":"CERT/CC Vulnerability Note is a limited advisory. It primarily identifies vendors impacted by the advisory and not specific products. We only support \"known_affected\" and \"known_not_affected\" status. Please consult the vendor's statements and advisory URL if provided by the vendor for more details ","title":"Limitations of Advisory"}],"publisher":{"category":"coordinator","contact_details":"Email: cert@cert.org, Phone: +1412 268 5800","issuing_authority":"CERT/CC under DHS/CISA https://www.cisa.gov/cybersecurity also see https://kb.cert.org/ ","name":"CERT/CC","namespace":"https://kb.cert.org/"},"references":[{"url":"https://certcc.github.io/certcc_disclosure_policy","summary":"CERT/CC vulnerability disclosure policy"},{"summary":"CERT/CC document released","category":"self","url":"https://kb.cert.org/vuls/id/369611"}],"title":"ExLlamaV3 contains Denial of Service vulnerability via insufficient bounds checking on kernel dispatch index","tracking":{"current_release_date":"2026-09-11T20:11:37+00:00","generator":{"engine":{"name":"VINCE","version":"3.0.45"}},"id":"VU#369611","initial_release_date":"2026-09-11 20:11:37.732697+00:00","revision_history":[{"date":"2026-09-11T20:11:37+00:00","number":"1.20260911201137.1","summary":"Released on 2026-09-11T20:11:37+00:00"}],"status":"final","version":"1.20260911201137.1"}},"vulnerabilities":[{"title":"ExLlamaV3’s EXL3 loader uses an untrusted, model-supplied index to select a CUDA kernel without first verifying that the index is within bounds.","notes":[{"category":"summary","text":"ExLlamaV3’s EXL3 loader uses an untrusted, model-supplied index to select a CUDA kernel without first verifying that the index is within bounds. A malicious model can force the code to read and invoke an out‑of‑range function pointer, resulting in a reproducible crash. Under specific conditions involving certain host memory layouts, it may be possible for an attacker to exploit this vulnerability to achieve controlled indirect kernel dispatch during model load."}],"cve":"CVE-2026-84286","ids":[{"system_name":"CERT/CC V Identifier ","text":"VU#369611"}]}],"product_tree":{"branches":[]}}