Vulnerability in Linux
CVE-2026-23448
In the Linux kernel, the following vulnerability has been resolved: net: usb: cdc_ncm: add ndpoffset to NDP16 nframes bounds check cdc_ncm_rx_verify_ndp16() validates that the NDP header and its DPE entries fit within the skb. The first check correctly accounts for ndpoffset: if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) but the second check omits it: if ((sizeof(struct usb_cdc_ncm_ndp16) + ret * (sizeof(struct usb_cdc_ncm_dpe16))) > skb_in->len) This validates the DPE array size against the total skb length as if the NDP were at offset 0, rather than at ndpoffset. When the NDP is placed near the end of the NTB (large wNdpIndex), the DPE entries can extend past the skb data buffer even though the check passes. cdc_ncm_rx_fixup() then reads out-of-bounds memory when iterating the DPE array. Add ndpoffset to the nframes bounds check and use struct_size_t() to express the NDP-plus-DPE-array size more clearly.
EPSS: 0.001 (2.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Linux — versions ff06ab13a4ccae4acb44a2d4e3ece367b616ab50, 3.8, 0
- Linux Linux_kernel — versions 7.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-23448?
- CVE-2026-23448 is a high-severity vulnerability in Linux, classified under Improper Validation of Array Index. CVSS score: 7.8/10. Published 2026-04-03.
- How severe is CVE-2026-23448?
- High severity. CVSS v3 base score is 7.8 out of 10.