CVE-2026-68368: In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: validate datagram bounds in ncm_unwrap_ntb() When unpacking ...

Description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: validate datagram bounds in ncm_unwrap_ntb() When unpacking host-supplied NTBs, ncm_unwrap_ntb() checks datagram length against frame_max but does not verify that the datagram fits within the declared block length. Additionally, when decoding multiple NTBs from a single socket buffer, subsequent block lengths are not checked against the actual remaining buffer data. With these checks missing, a malicious USB host can specify datagram offsets and lengths that point beyond the block, or supply secondary NTB headers declaring lengths larger than the buffer. skb_put_data() then copies adjacent kernel memory from skb_shared_info into the network skb. Fix this by verifying that sufficient buffer space remains for the NTB header before parsing, handling zero-length block declarations, ensuring that block lengths never exceed the remaining buffer space, and verifying that each datagram payload stays strictly within the block boundary.

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52, < e07751d0527ccc2a1c32eb0b0b7da3b4b9b5381f; >= 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52, < fff1059d139ef798bab917990524faaf25854ca8; >= 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52, < 40c706a0224bde194667e3378c689b542fec4b44; >= 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52, < 41fd5f2fb0027d3773ae949e3247c2e0a2a7fe5c; >= 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52, < 1febec7e47cdcd01f43fb0211094e3010474666e; f7e0611e207d8908c4f2858e244370529a76dbf7; b88ad6e714284b33a47834f5f2a294c2b37c66aa; 471b23586387a32857778c511be60ab31c98dcfd; 4f529c4d1e436230d3af7c09a3239677a14d2b46; ae6a5394d9fbe118bc95cfe376d6a9d91d7547e8; 5bdf93a2f5459f944b416b188178ca4a92fd206f; ff3ba016263ee93a1c6209bf5ab1599de7ab1512; e7ca00f35d8a17af1ae19d529193ebc21bfda164; >= 4.9.235, < 4.10; >= 4.14.196, < 4.15; >= 4.19.143, < 4.20; >= 5.4.62, < 5.5; >= 5.8.6, < 5.9; >= 4.14.328, < 4.15; >= 4.19.297, < 4.20; >= 5.4.259, < 5.5
Linux	Linux	5.9

References

Timeline

Published: Aug 10, 2026
Last Modified: Aug 10, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-68368?

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: validate datagram bounds in ncm_unwrap_ntb() When unpacking host-supplied NTBs, ncm_unwrap_ntb() checks datagram length against frame_max but does not verify that the datagram fits within the declared block length. Additionally, when decoding multiple NTBs from a single socket buffer, subsequent block lengths are not checked against the actual remaining buffer data. With these checks missing, a malicious USB host can specify datagram offsets and lengths that point beyond the block, or supply secondary NTB headers declaring lengths larger than the buffer. skb_put_data() then copies adjacent kernel memory from skb_shared_info into the network skb. Fix this by verifying that sufficient buffer space remains for the NTB header before parsing, handling zero-length block declarations, ensuring that block lengths never exceed the remaining buffer space, and verifying that each datagram payload stays strictly within the block boundary.

How severe is CVE-2026-68368?

Severity scoring for CVE-2026-68368 is pending analysis.

How do I fix CVE-2026-68368?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

View all 2026CVEs →