High 8.8Published Oct 28, 2025

CVE-2025-40043net: nfc: nci: Add parameter validation for packet data

Updated under an hour ago (Oct 27, 2026, 12:40 PM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: net: nfc: nci: Add parameter validation for packet data Syzbot reported an uninitialized value bug in nci_init_req, which was introduced by commit 5aca7966d2a7 ("Merge tag 'perf-tools-fixes-for-v6.17-2025-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools"). This bug arises due to very limited and poor input validation that was done at nic_valid_size(). This validation only validates the skb->len (directly reflects size provided at the userspace interface) with the length provided in the buffer itself (interpreted as NCI_HEADER). This leads to the processing of memory content at the address assuming the correct layout per what opcode requires there. This leads to the accesses to buffer of `skb_buff->data` which is not assigned anything yet. Following the same silent drop of packets of invalid sizes at `nic_valid_size()`, add validation of the data in the respective handlers and return error values in case of failure. Release the skb if error values are returned from handlers in `nci_nft_packet` and effectively do a silent drop Possible TODO: because we silently drop the packets, the call to `nci_request` will be waiting for completion of request and will face timeouts. These timeouts can get excessively logged in the dmesg. A proper handling of them may require to export `nci_request_cancel` (or propagate error handling from the nft packets handlers).

CVSS: 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Deferred
Record last updated: Aug 5, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 8fcc7315a10a84264e55bb65ede10f0af20a983f; from 6a2968aaf50c7a22fced77a5e24aa636281efca8 before bfdda0123dde406dbff62e7e9136037e97998a15; 6a2968aaf50c7a22fced77a5e24aa636281efca8 builds before 0ba68bea1e356f466ad29449938bea12f5f3711f; from 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 74837bca0748763a77f77db47a0bdbe63b347628; from 6a2968aaf50c7a22fced77a5e24aa636281efca8 before c395d1e548cc68e84584ffa2e3ca9796a78bf7b9; from 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 9c328f54741bd5465ca1dc717c84c04242fac2e1	CNA record

References

References

https://git.kernel.org/stable/c/8fcc7315a10a84264e55bb65ede10f0af20a983f
https://git.kernel.org/stable/c/bfdda0123dde406dbff62e7e9136037e97998a15
https://git.kernel.org/stable/c/0ba68bea1e356f466ad29449938bea12f5f3711f
https://git.kernel.org/stable/c/74837bca0748763a77f77db47a0bdbe63b347628
https://git.kernel.org/stable/c/c395d1e548cc68e84584ffa2e3ca9796a78bf7b9
https://git.kernel.org/stable/c/9c328f54741bd5465ca1dc717c84c04242fac2e1

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.