{"id":"CVE-2026-29645","state":"PUBLISHED","title":"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","description":"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.","publishedAt":"2026-04-20T00:00:00.000Z","updatedAt":"2026-04-21T19:51:06.424Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"CISA-ADP"},"assigner":"mitre","products":["n/a n/a"],"affected":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}],"references":["https://github.com/OpenXiangShan/NEMU/issues/952","https://github.com/OpenXiangShan/NEMU/pull/958","https://github.com/OpenXiangShan/NEMU/commit/481de637d5fc5838356caee80a79e56a33754039","https://docs.riscv.org/reference/isa/unpriv/v-st-ext.html"],"weaknesses":["CWE-131","CWE-1287"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/29xxx/CVE-2026-29645.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-29645","state":"PUBLISHED","datePublished":"2026-04-20T00:00:00.000Z","dateUpdated":"2026-04-21T19:51:06.424Z","assignerShortName":"mitre","assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateReserved":"2026-03-04T00:00:00.000Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}],"references":[{"url":"https://github.com/OpenXiangShan/NEMU/issues/952"},{"url":"https://github.com/OpenXiangShan/NEMU/pull/958"},{"url":"https://github.com/OpenXiangShan/NEMU/commit/481de637d5fc5838356caee80a79e56a33754039"},{"url":"https://docs.riscv.org/reference/isa/unpriv/v-st-ext.html"}],"problemTypes":[{"descriptions":[{"type":"text","lang":"en","description":"n/a"}]}],"providerMetadata":{"shortName":"mitre","orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateUpdated":"2026-04-20T19:24:42.410Z"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.5,"attackVector":"NETWORK","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"NONE","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-04-21T13:33:07.838848Z","id":"CVE-2026-29645","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-131","type":"CWE","lang":"en","description":"CWE-131 Incorrect Calculation of Buffer Size"}]},{"descriptions":[{"cweId":"CWE-1287","type":"CWE","lang":"en","description":"CWE-1287 Improper Validation of Specified Type of Input"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-21T19:51:06.424Z"}}]}}}