{"cve":"CVE-2026-64264","nvd":{"published":"2026-07-25T10:17:06.563","modified":"2026-08-17T05:17:25.170","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: fix EFAULT clobber in fuse_uring_commit\n\ncopy_from_user() returns the number of bytes not copied as an unsigned\nresidual on failure (1..sizeof(struct fuse_out_header)). fuse_uring_commit\nstores that residual in ssize_t err, sets req->out.h.error to -EFAULT,\nthen jumps to out: with err still holding the positive residual.\n\n    err = copy_from_user(&req->out.h, &ent->headers->in_out,\n                         sizeof(req->out.h));\n    if (err) {\n        req->out.h.error = -EFAULT;\n        goto out;          /* err is the positive residual */\n    }\n    ...\n    out:\n        fuse_uring_req_end(ent, req, err);\n\nfuse_uring_req_end() then runs\n\n    if (error)\n        req->out.h.error = error;\n\nwhich overwrites the just-assigned -EFAULT with the positive residual.\nFUSE callers such as fuse_simple_request() test err < 0 to detect\nfailure, so the positive value is interpreted as success and the\ncaller proceeds with an uninitialised or partial req->out.args.\n\nFix by assigning err = -EFAULT in the failure branch before jumping\nto out, so fuse_uring_req_end() receives a negative errno and sets\nreq->out.h.error to -EFAULT.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/0483fffdeeb363f320e6bf5fc0f0306007507306","https://git.kernel.org/stable/c/3a0a8bc51a13951c5141262bf770eeea3e0b6228","https://git.kernel.org/stable/c/fe604c08d874648a69187f6380e5c7858627dc04"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:46:40.600842820+00:00"},"epss":{"cve":"CVE-2026-64264","score":0.0016,"percentile":0.05167,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}