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NVD / CVE Program· CNA Linux

CVE-2026-89621: HID: mcp2221: validate report size in mcp2221_raw_event()

—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.22% (FIRST EPSS).
  • Fixed version: Linux Linux 127de5919820f88a9d55e8371ad4ac49f625f4c5, 2c9a6998c19503626c57a2267bf279e204113079, 7c18fb36708a97ff6772825cc087b6d537bbf0d5.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 127de5919820f88a9d55e8371ad4ac49f625f4c5, 2c9a6998c19503626c57a2267bf279e204113079, 7c18fb36708a97ff6772825cc087b6d537bbf0d5 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: HID: mcp2221: validate report size in mcp2221_raw_event() mcp2221_raw_event() never validates the size of incoming HID reports. In the MCP2221_I2C_GET_DATA path it trusts the device-supplied data[3] as the copy length without checking that 4 + data[3] bytes actually exist in the received report. A malicious or misbehaving USB device can send a short report with a large data[3], causing the memcpy to read past the valid report data in the HID transfer buffer and leak uninitialized kernel memory back to userspace through the I2C/SMBus read path. Add a minimum size check at entry and validate that the source range fits within the received report before the copy.

Published
Sep 11, 2026
Updated
Oct 19, 2026
EPSS
0.2% · 12th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Follow CVE-2026-89621

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  • when exploit code appears or is weaponized
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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.7affected
    • 67a95c21463d066060b0f66d65a75d45bb386ffb and later · before cb38b1f149b7143355b37e86c841acf0076e5c2aaffected · git
    • 67a95c21463d066060b0f66d65a75d45bb386ffb and later · before b2c67dc0e30c308647bbd9b9e5d69a44c9d2733daffected · git
    • 67a95c21463d066060b0f66d65a75d45bb386ffb and later · before fffcfa367072628c3144cca17d2a3c3c9e50c057affected · git
    • 67a95c21463d066060b0f66d65a75d45bb386ffb and later · before c1c508e8923911cb458234997e55b7a4b9aa066faffected · git
    • 67a95c21463d066060b0f66d65a75d45bb386ffb and later · before bdc6a3af0dd734a326acdb7d6401a3b6a9f4f149affected · git
    • 67a95c21463d066060b0f66d65a75d45bb386ffb and later · before 127de5919820f88a9d55e8371ad4ac49f625f4c5affected · git
    • 67a95c21463d066060b0f66d65a75d45bb386ffb and later · before 7c18fb36708a97ff6772825cc087b6d537bbf0d5affected · git
    • 67a95c21463d066060b0f66d65a75d45bb386ffb and later · before 2c9a6998c19503626c57a2267bf279e204113079affected · git
    • before 5.7not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-89619Sep 11, 2026 · HID: intel-thc-hid: intel-quickspi: bound GET_REPORT response to the caller buffer
    31Monitor
  • ← EarlierCVE-2026-89620Sep 11, 2026 · HID: intel-thc-hid: intel-quickspi: validate report size before copy
    31Monitor
  • Later →CVE-2026-89622Sep 11, 2026 · HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux127de5919820f88a9d55e8371ad4ac49f625f4c5Vendor (CNA)
Linux Linux2c9a6998c19503626c57a2267bf279e204113079Vendor (CNA)
Linux Linux7c18fb36708a97ff6772825cc087b6d537bbf0d5Vendor (CNA)
Linux Linuxb2c67dc0e30c308647bbd9b9e5d69a44c9d2733dVendor (CNA)
Linux Linuxbdc6a3af0dd734a326acdb7d6401a3b6a9f4f149Vendor (CNA)
Linux Linuxc1c508e8923911cb458234997e55b7a4b9aa066fVendor (CNA)
Linux Linuxcb38b1f149b7143355b37e86c841acf0076e5c2aVendor (CNA)
Linux Linuxfffcfa367072628c3144cca17d2a3c3c9e50c057Vendor (CNA)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records