CVE-2026-63963

Kernel data disclosure via unchecked VDO count

Published Jul 19, 2026 · Updated Jul 19, 2026

Out-of-bounds read in Linux Kernel allows physically proximate attackers to disclose kernel data through a crafted USB-C identity response. The TCPM Discover Identity ACK handlers pass a device-controlled VDO count to svdm_consume_identity() or svdm_consume_identity_sop_prime() without checking the static identity-array bounds. Exploitation requires a connected USB Type-C partner to return an oversized VDO count, causing reads beyond those arrays and disclosure of adjacent kernel data.

CVSS severity7.1
High
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

Out-of-bounds read in Linux Kernel allows physically proximate attackers to disclose kernel data through a crafted USB-C identity response. The TCPM Discover Identity ACK handlers pass a device-controlled VDO count to svdm_consume_identity() or svdm_consume_identity_sop_prime() without checking the static identity-array bounds. Exploitation requires a connected USB Type-C partner to return an oversized VDO count, causing reads beyond those arrays and disclosure of adjacent kernel data.

The record

CVE
CVE-2026-63963
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=0 <6.12.93
  2. Affected versionversion=0 <6.18.35
  3. Affected versionversion=0 <7.0.12
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <569f7971542eb10025d8a0989b83f28a29d8ba20
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8fbc349e8383125dd2d8de1c1e926279d398ab17
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ed8649f3822e211d025bcab5158af6f8a38c8705
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f9d787fbe83127105e42088cca40e5118db0d810

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0 <6.12.93; version=0 <6.18.35; version=0 <7.0.12; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <569f7971542eb10025d8a0989b83f28a29d8ba20; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8fbc349e8383125dd2d8de1c1e926279d398ab17; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ed8649f3822e211d025bcab5158af6f8a38c8705; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f9d787fbe83127105e42088cca40e5118db0d810

Published CVSS scores

7.1TenableCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
5.6TenableAV:L/AC:L/Au:N/C:P/I:N/A:C

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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