CVE-2026-63932

Kernel buffer overwrite via oversized serial reply

Published Jul 19, 2026 · Updated Jul 19, 2026

Buffer overflow in the Linux Kernel MH-Z19B IIO driver allows attackers controlling a serial peer to overwrite kernel memory. mhz19b_receive_buf() copies each callback chunk into the fixed MHZ19B_CMD_SIZE buffer and advances buf_idx without checking the remaining capacity. Reachability requires an oversized reply from a serial peer; published evidence establishes the overwrite but not a resulting crash or code execution.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in the Linux Kernel MH-Z19B IIO driver allows attackers controlling a serial peer to overwrite kernel memory. mhz19b_receive_buf() copies each callback chunk into the fixed MHZ19B_CMD_SIZE buffer and advances buf_idx without checking the remaining capacity. Reachability requires an oversized reply from a serial peer; published evidence establishes the overwrite but not a resulting crash or code execution.

The record

CVE
CVE-2026-63932
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
Unavailable
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4572a70b3681e38055c78d12fb68cd147bdbee7d <673478bc29cf72010faaf293c1c8c667393335a0
  2. Affected versionversion=4572a70b3681e38055c78d12fb68cd147bdbee7d <a5a05410cb34bfa486d63684cdc1f87a3b13f20a
  3. Affected versionversion=4572a70b3681e38055c78d12fb68cd147bdbee7d <ea69e7a6efa88ef32090a91064c362738cc19ddd
  4. Affected versionversion=6.16

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4572a70b3681e38055c78d12fb68cd147bdbee7d <673478bc29cf72010faaf293c1c8c667393335a0; version=4572a70b3681e38055c78d12fb68cd147bdbee7d <a5a05410cb34bfa486d63684cdc1f87a3b13f20a; version=4572a70b3681e38055c78d12fb68cd147bdbee7d <ea69e7a6efa88ef32090a91064c362738cc19ddd; version=6.16

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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