usb: misc: usbio: check ibuf_len against rxbuf_len in bulk msg (CVE-2026-74681) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-74681

usb: misc: usbio: check ibuf_len against rxbuf_len in bulk msg

Answer in brief

CVE-2026-74681 records a Unknown severity vulnerability in usb: misc: usbio: check ibuf_len against rxbuf_len in bulk msg. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 22, 2026Updated Aug 22, 2026Source checked Aug 22, 2026First seen by HOL Aug 22, 2026Material review Aug 22, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=121a0f839dbb397af5fabb701cea3e9983223e50 <ebfd1e82ab0a6d26efd9bdd89de899215851f5bf \|\| >=121a0f839dbb397af5fabb701cea3e9983223e50 <9ad0164f78b66b0b5eca3a5748cc94dd87e28124 \|\| >=121a0f839dbb397af5fabb701cea3e9983223e50 <7e22c9f79b200672f3e477421b6c9050d8cf70a5	ebfd1e82ab0a6d26efd9bdd89de899215851f5bf, 9ad0164f78b66b0b5eca3a5748cc94dd87e28124, 7e22c9f79b200672f3e477421b6c9050d8cf70a5
Linux/Linuxgeneric	6.18	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to ebfd1e82ab0a6d26efd9bdd89de899215851f5bf if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 22, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: usb: misc: usbio: check ibuf_len against rxbuf_len in bulk msg ibuf_len is the bulk IN (receive) buffer size, but the EMSGSIZE check in usbio_bulk_msg() compares it against txbuf_len — the bulk OUT endpoint size. Both are taken independently from different endpoints in usbio_probe(), so the check is wrong when they differ. Use rxbuf_len for the IN direction. This matches the buffer that actually holds the response data.

Quoted source text, attributed separately from HOL analysis.