Evidence-led vulnerability intelligence · 2026-09-04 21:48 IST

CVE-2026-80781

In the Linux kernel, the following vulnerability has been resolved: HID: core: fix OOB read of field->usage in hid_set_field() hid_set_field() hands field->usage + offset to hid_dump_input() before the guard that bounds offset: hid_dump_input(field->report->device, field->usage + offset, value); if (offset >= field->report_count) { hid_err(...); return -1; } Under CONFIG_DEBUG_FS hid_dump_input() dereferences that pointer, with buf = hid_resolv_usage(usage->hid, NULL). The usage[] array is allocated inline with the hid_field in hid_register_field() and holds field->maxusage entries, so an offset past it reads off the end of the kvzalloc()ed allocation and into a neighbouring object. Had the guard run first, offset < report_count <= maxusage would already have confined the pointer to the array. A caller supplies such an offset today. picolcd_fb_send_tile() validates only report->maxfield before issuing hid_set_field(report->field[0], 11 + i, ...) for i = 0..31, so its offsets are fixed at 11..42 and are never checked against the bound field. When the device registers that field with fewer usages, the framebuffer deferred-io work drives the read on every tile. KASAN reports a 4-byte slab-out-of-bounds read in hid_dump_input() below hid_set_field(), and the same boot logs "offset (1) exceeds report_count (1)" from the guard that runs only afterwards. Move the hid_dump_input() call below the guard. Because field->maxusage >= field->report_count, the guard then establishes that field->usage + offset lies inside the array before it is dereferenced, for every caller and without changing behaviour on the valid path. Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>

UNRATED · N/ALinux

Executive briefing

The source record describes: In the Linux kernel, the following vulnerability has been resolved: HID: core: fix OOB read of field->usage in hid_set_field() hid_set_field() hands field->usage + offset to hid_dump_input() before the guard that bounds offset: hid_dump_input(field->report->device, field->usage + offset, value); if (offset >= field->report_count) { hid_err(...); return -1; } Under CONFIG_DEBUG_FS hid_dump_input() dereferences that pointer, with buf = hid_resolv_usage(usage->hid, NULL). The usage[] array is allocated inline with the hid_field in hid_register_field() and holds field->maxusage entries, so an offset past it reads off the end of the kvzalloc()ed allocation and into a neighbouring object. Had the guard run first, offset < report_count <= maxusage would already have confined the pointer to the array. A caller supplies such an offset today. picolcd_fb_send_tile() validates only report->maxfield before issuing hid_set_field(report->field[0], 11 + i, ...) for i = 0..31, so its offsets are fixed at 11..42 and are never checked against the bound field. When the device registers that field with fewer usages, the framebuffer deferred-io work drives the read on every tile. KASAN reports a 4-byte slab-out-of-bounds read in hid_dump_input() below hid_set_field(), and the same boot logs "offset (1) exceeds report_count (1)" from the guard that runs only afterwards. Move the hid_dump_input() call below the guard. Because field->maxusage >= field->report_count, the guard then establishes that field->usage + offset lies inside the array before it is dereferenced, for every caller and without changing behaviour on the valid path. Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com> The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.

Assessment: Potential exposure only — validate the installed product, exact version, configuration and vendor applicability before treating an asset as confirmed vulnerable.

Evidence confidence: Limited Evidence-derived, not an exploitability verdict

Severity & attack characteristics

N/A / 10 ·

CVSS vector:

No CVSS vector is currently available in the source record.

Technical explanation & impact

The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.

Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.

Affected products and versions

NVD has not supplied machine-readable vulnerable CPE product/version entries for this CVE. This is an information gap, not proof that no products are affected. Check the vendor advisory references below.

Remediation & validation

  1. Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
  2. Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
  3. Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
  4. Validate the remediation with a version check and vulnerability rescan, then retain change evidence.

No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.

Vendor advisories, patches & exploit references

Information gaps & confidence notes

These gaps indicate missing source data. CVE Watch does not fill them with guessed product, exploit or patch details.

Last enrichment: 2026-11-07T16:58:38+00:00 · Source last modified: 2026-11-06T17:19:58.370

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Threat intelligence, made actionable · CVE data sourced from the NVD