CVE-2026-63957

Physical kernel slab corruption via undersized endpoint

Published Jul 19, 2026 · Updated Jul 19, 2026

Memory corruption in Linux Kernel safe_serial allows physically proximate attackers to corrupt kernel slab memory via a malicious USB device. The startup path accepted a bulk-out endpoint smaller than eight bytes even though safe-mode writes reserve space for a two-byte trailer in that buffer. Exploitation requires an attached device that advertises an undersized endpoint and reaches safe mode; the published record establishes slab corruption but not code execution.

CVSS severityUnavailable
Unscored
EPSS probability0.22%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in Linux Kernel safe_serial allows physically proximate attackers to corrupt kernel slab memory via a malicious USB device. The startup path accepted a bulk-out endpoint smaller than eight bytes even though safe-mode writes reserve space for a two-byte trailer in that buffer. Exploitation requires an attached device that advertises an undersized endpoint and reaches safe mode; the published record establishes slab corruption but not code execution.

The record

CVE
CVE-2026-63957
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1200
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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <161ea0e5236f5f051d2d85d6c54dd08ee9dc7ba4
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <438061ed1ad85e6743e2dce826671772d81089ec
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <857b3cc73f91871ae4433f8b97c4670b78f8dc96
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9b3145b3001fb24de1da72d1deb0bea70e5a078b
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a550ed2117ca4709d38f713933ff924a83942e41
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c7336c0fba5c959249f3d793d33076b992ec3ee4
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e3a1d6eee25dc96b1d2db0ecd9d8741e92056476
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f793b67d41e5fab719c5a90baa77cbd2fe259517
  9. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <161ea0e5236f5f051d2d85d6c54dd08ee9dc7ba4; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <438061ed1ad85e6743e2dce826671772d81089ec; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <857b3cc73f91871ae4433f8b97c4670b78f8dc96; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9b3145b3001fb24de1da72d1deb0bea70e5a078b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a550ed2117ca4709d38f713933ff924a83942e41; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c7336c0fba5c959249f3d793d33076b992ec3ee4; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e3a1d6eee25dc96b1d2db0ecd9d8741e92056476; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f793b67d41e5fab719c5a90baa77cbd2fe259517; version=2.6.12

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 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1200Hardware Additions

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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