{"cve":"CVE-2026-89571","nvd":{"published":"2026-09-11T20:19:41.160","modified":"2026-10-19T09:17:53.003","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/features: bound fwctl command payload to the input buffer\n\nfwctl_cmd_rpc() copies cmd->in_len bytes into inbuf = kvzalloc(cmd->in_len)\nand passes inbuf and in_len to ->fw_rpc(). The CXL callback cxlctl_fw_rpc()\nignores in_len and never checks the user-controlled op_size against it.\n\ncxlctl_set_feature() bounds op_size only from below\n(op_size <= sizeof(feat_in->hdr)) and then reads op_size - sizeof(hdr)\nbytes from feat_in->feat_data via cxl_set_feature(). With a small in_len\nand a large op_size the first memcpy() already reads past the\nkvzalloc(in_len) buffer; the out-of-bounds bytes are placed in the mailbox\npayload and sent to the device, and a large enough op_size can walk into\nunmapped memory and oops the kernel. The Get paths pin op_size to a fixed\nsize but likewise read the input struct without checking in_len.\n\nReject, at the single dispatch point, any request whose fixed header plus\nop_size does not fit in the copied-in buffer. The lower-bound test guards\nthe subtraction and ensures op_size was copied in before it is read.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","score":7.1},"cwes":[],"references":["https://git.kernel.org/stable/c/14d52c15d5d99477b20a2d61fe36f347080da6cd","https://git.kernel.org/stable/c/d8957545fe96f7905791c937758ebfc1ae1e5b17","https://git.kernel.org/stable/c/f687394af983df5660b6afae7e0d06969f3af206"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:53:43.293028046+00:00"},"epss":{"cve":"CVE-2026-89571","score":0.00164,"percentile":0.05571,"date":"2026-10-25"},"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."]}