{"id":"CVE-2026-29645","details":"NEMU (OpenXiangShan/NEMU) before v2025.12.r2 contains an improper instruction-validation flaw in its RISC-V Vector (RVV) decoder. The decoder does not correctly validate the funct3 field when decoding vsetvli/vsetivli/vsetvl, allowing certain invalid OP-V instruction encodings to be misinterpreted and executed as vset* configuration instructions rather than raising an illegal-instruction exception. This can be exploited by providing crafted RISC-V binaries to cause incorrect trap behavior, architectural state corruption/divergence, and potential denial of service in systems that rely on NEMU for correct execution or sandboxing.","modified":"2026-07-15T01:49:11.692897869Z","published":"2026-04-20T00:00:00Z","database_specific":{"cna_assigner":"mitre","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/29xxx/CVE-2026-29645.json"},"references":[{"type":"WEB","url":"https://docs.riscv.org/reference/isa/unpriv/v-st-ext.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/29xxx/CVE-2026-29645.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-29645"},{"type":"REPORT","url":"https://github.com/OpenXiangShan/NEMU/issues/952"},{"type":"FIX","url":"https://github.com/OpenXiangShan/NEMU/commit/481de637d5fc5838356caee80a79e56a33754039"},{"type":"FIX","url":"https://github.com/OpenXiangShan/NEMU/pull/958"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/openxiangshan/nemu","events":[{"introduced":"304d1da6a1bae861be9dbf2f6a299cf1c47f383d"},{"fixed":"481de637d5fc5838356caee80a79e56a33754039"}],"database_specific":{"extracted_events":[{"introduced":"2025.12-r1"},{"last_affected":"2025.12-r1"}],"source":["CPE_STRING","REFERENCES"],"cpe":"cpe:2.3:a:xiangshan:nemu:2025.12:r1:*:*:*:*:*:*"}}],"versions":["2025.12-r1","v2025.12.r1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-29645.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}