{"cve":"CVE-2025-40043","nvd":{"published":"2025-10-28T12:15:38.333","modified":"2026-10-19T21:10:00.160","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: nfc: nci: Add parameter validation for packet data\n\nSyzbot reported an uninitialized value bug in nci_init_req, which was\nintroduced by commit 5aca7966d2a7 (\"Merge tag\n'perf-tools-fixes-for-v6.17-2025-09-16' of\ngit://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools\").\n\nThis bug arises due to very limited and poor input validation\nthat was done at nic_valid_size(). This validation only\nvalidates the skb->len (directly reflects size provided at the\nuserspace interface) with the length provided in the buffer\nitself (interpreted as NCI_HEADER). This leads to the processing\nof memory content at the address assuming the correct layout\nper what opcode requires there. This leads to the accesses to\nbuffer of `skb_buff->data` which is not assigned anything yet.\n\nFollowing the same silent drop of packets of invalid sizes at\n`nic_valid_size()`, add validation of the data in the respective\nhandlers and return error values in case of failure. Release\nthe skb if error values are returned from handlers in\n`nci_nft_packet` and effectively do a silent drop\n\nPossible TODO: because we silently drop the packets, the\ncall to `nci_request` will be waiting for completion of request\nand will face timeouts. These timeouts can get excessively logged\nin the dmesg. A proper handling of them may require to export\n`nci_request_cancel` (or propagate error handling from the\nnft packets handlers).","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":[],"references":["https://git.kernel.org/stable/c/0ba68bea1e356f466ad29449938bea12f5f3711f","https://git.kernel.org/stable/c/74837bca0748763a77f77db47a0bdbe63b347628","https://git.kernel.org/stable/c/8fcc7315a10a84264e55bb65ede10f0af20a983f","https://git.kernel.org/stable/c/9c328f54741bd5465ca1dc717c84c04242fac2e1","https://git.kernel.org/stable/c/bfdda0123dde406dbff62e7e9136037e97998a15"],"products":[],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-40043","score":0.00314,"percentile":0.24114,"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."]}