{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64082", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.031Z", "datePublished": "2026-07-19T15:39:54.074Z", "dateUpdated": "2026-09-02T12:49:41.782Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-02T12:49:41.782Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nriscv: Fix register corruption from uninitialized cregs on error\n\ncompat_riscv_gpr_set() calls cregs_to_regs() unconditionally, even when\nuser_regset_copyin() fails. Since cregs is an uninitialized stack\nvariable, a copyin failure causes uninitialized stack data to be written\ninto the target task's pt_regs, corrupting its register state and\npotentially leaking kernel stack contents.\n\ncompat_restore_sigcontext() has the same issue: it calls cregs_to_regs()\neven when __copy_from_user() fails, leading to the same corruption of\nthe signal-returning task's register state on error.\n\nOnly call cregs_to_regs() when the user copy succeeds." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is only reachable through local kernel interfaces—compat_rt_sigreturn and ptrace(PTRACE_SETREGSET)—with no network, adjacent-radio, or physical-device code path involved.\nAC:L - An attacker can reliably force the user copy to fail by racing munmap/mprotect against sigreturn or ptrace SETREGSET after access_ok, controlling both sides of the TOCTOU window.\nPR:L - The lowest-privilege path is compat_rt_sigreturn, callable by any unprivileged 32-bit compat process on a CONFIG_COMPAT RISC-V system without capabilities or root.\nUI:N - Exploitation requires no victim interaction; a local attacker corrupts their own task’s registers via rt_sigreturn or a tracee they already control as parent/tracer.\nS:U - Impact is confined to kernel register-state corruption and information disclosure within the same OS security boundary, not a VM escape or cross-authority sandbox breakout.\nC:H - On copy failure, uninitialized kernel stack data (up to the full compat_user_regs_struct) is written into pt_regs, leaking kernel memory contents into user-observable registers.\nI:H - The corruption overwrites all general-purpose registers in pt_regs—including program counter, stack pointer, and return address—constituting memory corruption exploitable for control-flow hijacking.\nA:H - Corrupted pt_regs reliably cause faults, SIGSEGV delivery, or erratic kernel/user execution, and the condition is repeatable for persistent denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/riscv/kernel/compat_signal.c", "arch/riscv/kernel/ptrace.c" ], "versions": [ { "version": "7383ee05314be58f8f9f018ee0ac53bef3808aea", "lessThan": "f2d88b0d7aebfa4643fc58bbae57210c6daff9c6", "status": "affected", "versionType": "git" }, { "version": "7383ee05314be58f8f9f018ee0ac53bef3808aea", "lessThan": "66dedb6028c3df6c6a3372dd935b823917e150d5", "status": "affected", "versionType": "git" }, { "version": "7383ee05314be58f8f9f018ee0ac53bef3808aea", "lessThan": "2a7d1daf2674fe7d5b1cc99a4e3b5f0f72d5958f", "status": "affected", "versionType": "git" }, { "version": "7383ee05314be58f8f9f018ee0ac53bef3808aea", "lessThan": "0599aa23734c48de9bce36d043a9ec90c23945a1", "status": "affected", "versionType": "git" }, { "version": "7383ee05314be58f8f9f018ee0ac53bef3808aea", "lessThan": "9e020156833f1ad0d425a1e3d85b65639f1c1c50", "status": "affected", "versionType": "git" }, { "version": "7383ee05314be58f8f9f018ee0ac53bef3808aea", "lessThan": "6ebcbb53fc9bc30843054ed99fd60b8e542628f4", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/riscv/kernel/compat_signal.c", "arch/riscv/kernel/ptrace.c" ], "versions": [ { "version": "5.19", "status": "affected" }, { "version": "0", "lessThan": "5.19", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.187", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.156", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.108", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.49", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.11", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.1.187" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.6.156" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.12.108" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.18.49" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "7.0.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f2d88b0d7aebfa4643fc58bbae57210c6daff9c6" }, { "url": "https://git.kernel.org/stable/c/66dedb6028c3df6c6a3372dd935b823917e150d5" }, { "url": "https://git.kernel.org/stable/c/2a7d1daf2674fe7d5b1cc99a4e3b5f0f72d5958f" }, { "url": "https://git.kernel.org/stable/c/0599aa23734c48de9bce36d043a9ec90c23945a1" }, { "url": "https://git.kernel.org/stable/c/9e020156833f1ad0d425a1e3d85b65639f1c1c50" }, { "url": "https://git.kernel.org/stable/c/6ebcbb53fc9bc30843054ed99fd60b8e542628f4" } ], "title": "riscv: Fix register corruption from uninitialized cregs on error", "x_generator": { "engine": "bippy-1.2.0" } } } }