Public vulnerability disclosure

CVE-2026-68368

usb: gadget: f_ncm: validate datagram bounds in ncm_unwrap_ntb()

published

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.

Technical severityUnscoredNo score in collected sources
Published2026-08-10Source updated 2026-11-06
Collected2026-11-062 attributed sources

Fixes and workarounds

No remediation reported in collected sources.

Missing remediation information is not evidence that no patch exists.

Affected products and versions

Affected products, source version ranges and reporting authorities
ProductVersionsAuthority
Linux
Linux
≥ 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52; < 35d15bbaec0557330e774ec31412ef508de6e0e0 (affected, git)
≥ 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52; < 6b2be489eaa6293e60549005d91f15ceb150510f (affected, git)
≥ 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52; < f87ed889f0f7417b8938c98d8833f559b755373c (affected, git)
≥ 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52; < e07751d0527ccc2a1c32eb0b0b7da3b4b9b5381f (affected, git)
≥ 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52; < fff1059d139ef798bab917990524faaf25854ca8 (affected, git)
≥ 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52; < 40c706a0224bde194667e3378c689b542fec4b44 (affected, git)
≥ 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52; < 41fd5f2fb0027d3773ae949e3247c2e0a2a7fe5c (affected, git)
≥ 2b74b0a04d3e9f9f08ff026e5663dce88ff94e52; < 1febec7e47cdcd01f43fb0211094e3010474666e (affected, git)
f7e0611e207d8908c4f2858e244370529a76dbf7 (affected, git)
b88ad6e714284b33a47834f5f2a294c2b37c66aa (affected, git)
471b23586387a32857778c511be60ab31c98dcfd (affected, git)
4f529c4d1e436230d3af7c09a3239677a14d2b46 (affected, git)
ae6a5394d9fbe118bc95cfe376d6a9d91d7547e8 (affected, git)
5bdf93a2f5459f944b416b188178ca4a92fd206f (affected, git)
ff3ba016263ee93a1c6209bf5ab1599de7ab1512 (affected, git)
e7ca00f35d8a17af1ae19d529193ebc21bfda164 (affected, git)
≥ 4.9.235; < 4.10 (affected, semver)
≥ 4.14.196; < 4.15 (affected, semver)
≥ 4.19.143; < 4.20 (affected, semver)
≥ 5.4.62; < 5.5 (affected, semver)
≥ 5.8.6; < 5.9 (affected, semver)
≥ 4.14.328; < 4.15 (affected, semver)
≥ 4.19.297; < 4.20 (affected, semver)
≥ 5.4.259; < 5.5 (affected, semver)
Other versions: unaffected
CNA: Linux
Linux
Linux
5.9 (affected)
≥ 0; < 5.9 (unaffected, semver)
≥ 5.10.265; ≤ 5.10.* (unaffected, semver)
≥ 5.15.216; ≤ 5.15.* (unaffected, semver)
≥ 6.1.183; ≤ 6.1.* (unaffected, semver)
≥ 6.6.148; ≤ 6.6.* (unaffected, semver)
≥ 6.12.101; ≤ 6.12.* (unaffected, semver)
≥ 6.18.42; ≤ 6.18.* (unaffected, semver)
≥ 7.1.6; ≤ 7.1.* (unaffected, semver)
≥ 7.2; ≤ * (unaffected, original_commit_for_fix)
Other versions: affected
CNA: Linux

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

No CVSS assessment reported. An unscored record is not a low-severity determination.

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

For agents and automation

Read public disclosures for free as Markdown or JSON. Compatible browsers also expose native WebMCP tools to search disclosures, read this page, and discover API access.

Use the ontology-linked Cyber API with x402 pay per request, or a Y2 Pro or Elite API key with the intel:cyber scope.

Endpoints and access details

https://api.y2.dev/api/v2/cyber/cves
https://api.y2.dev/api/v2/cyber/cves/{cveId}

A workspace owner or admin can create a Pro or Elite API key. Send Authorization: Bearer <Y2_API_KEY> from your trusted agent runtime.

For x402, omit Authorization and read the HTTP 402 payment challenge before signing a retry. Public browser tools do not make payments.

Agent access JSON · OpenAPI · CVE API guide