{"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":"2026-08-12T16:24:57.013626Z","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","vanir_signatures_modified":"2026-08-12T16:24:57Z","vanir_signatures":[{"signature_version":"v1","source":"https://github.com/openxiangshan/nemu/commit/481de637d5fc5838356caee80a79e56a33754039","target":{"file":"src/isa/riscv64/instr/rvv/decode.h","function":"def_THelper"},"deprecated":false,"digest":{"function_hash":"50834913755908956887293910371665530495","length":3517},"id":"CVE-2026-29645-1418f832","signature_type":"Function"},{"signature_version":"v1","source":"https://github.com/openxiangshan/nemu/commit/481de637d5fc5838356caee80a79e56a33754039","target":{"file":"src/isa/riscv64/instr/rvv/decode.h","function":"def_THelper"},"deprecated":false,"digest":{"length":3483,"function_hash":"24588721114379366516345712678003273244"},"id":"CVE-2026-29645-47889a9d","signature_type":"Function"},{"deprecated":false,"digest":{"threshold":0.9,"line_hashes":["186451324716102190972272071777021467080","229570981201066192739628394813697023333","132071856606749338946419900215730130863","186451324716102190972272071777021467080","229570981201066192739628394813697023333","247603470448565063390777857171839702161","322746400276181205856657891894242633078","137468751287563319557364335998960762387","100213248681997610596256811947574100100","274932493952440577236124947020996803077","186127698557519673345741016229739660787","325572569331760299469915077948329398315","109942038229890815547476116952404105378","137181365460926217368801053239941746773","127266322390854122349285229130016279176","95089221874248222804286126970810762942","18965833649978219703230680148386518957","167487843857750677704134367455240108339","238584700931123364394569788698639272182","203039311245571140773994373311846990503","331092338172181110928374156392414411016","292332213698362928820480435518140015252","246930727414863390132532104043136519305","58663475041318529246635698343182346774","229050973800706818573142299085289025325","298468709598194239040696117087400515","244362994731705040120320154003066756715","262884823143525010375361286087472447350","218338611472923864689336719528282063340","184834275751066826559551513622269484968","85989341715439753882872678853312061328","118873928335077854386484288481004995642","184479131259141826728388788938043923278","336446458999131828933662515785525785037","313539753977305908031829827012703023806","139033953176906583302322010749631546901","274932493952440577236124947020996803077","68111385229264506927672077237264538133","16625862727491154684886155300607679957","64414056077635942418250290525166821001","90530142601496853616672834680695542839","309159293240473950483460901373532618792","118431433153021859218816168714902652743","276525100126957573901194296491186705645","172957600753516473743070292522836200861","149605954086344586250659080774853784887","168051098397139842562577482037386913553","172638255346239029027084767105208091355","137181365460926217368801053239941746773","127266322390854122349285229130016279176","95089221874248222804286126970810762942","18965833649978219703230680148386518957","167487843857750677704134367455240108339","238584700931123364394569788698639272182","203039311245571140773994373311846990503","331092338172181110928374156392414411016"]},"id":"CVE-2026-29645-9ea10220","signature_type":"Line","signature_version":"v1","source":"https://github.com/openxiangshan/nemu/commit/481de637d5fc5838356caee80a79e56a33754039","target":{"file":"src/isa/riscv64/instr/rvv/decode.h"}}]}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}