CVE-2026-63900

Kernel memory disclosure via truncated indat packet

Published Jul 19, 2026 · Updated Jul 19, 2026

Kernel memory disclosure in the Linux keyspan driver allows physically proximate attackers to read stale data via a malformed USA-49WG transfer. The usa49wg_indat_callback parser enters its packet loop without verifying that at least three header bytes remain, so a truncated USB transfer makes it parse stale or uninitialized slab contents. Exploitation requires a connected USA-49WG-compatible USB device able to submit a malformed indat packet; no data modification or service interruption is reported.

CVSS severity4.6
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Kernel memory disclosure in the Linux keyspan driver allows physically proximate attackers to read stale data via a malformed USA-49WG transfer. The usa49wg_indat_callback parser enters its packet loop without verifying that at least three header bytes remain, so a truncated USB transfer makes it parse stale or uninitialized slab contents. Exploitation requires a connected USA-49WG-compatible USB device able to submit a malformed indat packet; no data modification or service interruption is reported.

The record

CVE
CVE-2026-63900
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=0ca1268e109acf6d71507398cb95cab2e670b654 <0bde5431037a076ff3750da2165fd77a6f5ff058
  2. Affected versionversion=0ca1268e109acf6d71507398cb95cab2e670b654 <3759a40738b83bb61699c85f063202b514b94f77
  3. Affected versionversion=0ca1268e109acf6d71507398cb95cab2e670b654 <41d9673941eebdde62ee73848fcfe4ae1105c979
  4. Affected versionversion=0ca1268e109acf6d71507398cb95cab2e670b654 <ab8336a7e414f018430aa1af3a46944032f7ff96
  5. Affected versionversion=0ca1268e109acf6d71507398cb95cab2e670b654 <bd6c5fe59f374b63173afe5cf0ab38a9a370f2c1
  6. Affected versionversion=0ca1268e109acf6d71507398cb95cab2e670b654 <e124120e89b61a967e40dee6b5e1ecafc45c09d9
  7. Affected versionversion=0ca1268e109acf6d71507398cb95cab2e670b654 <ea2b792330b44b6d7ce671c3e1d59d0c121f7ed1
  8. Affected versionversion=0ca1268e109acf6d71507398cb95cab2e670b654 <f7f566ad7519c7ca3bc9071350002940a2b0e22a
  9. Affected versionversion=2.6.23

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0ca1268e109acf6d71507398cb95cab2e670b654 <0bde5431037a076ff3750da2165fd77a6f5ff058; version=0ca1268e109acf6d71507398cb95cab2e670b654 <3759a40738b83bb61699c85f063202b514b94f77; version=0ca1268e109acf6d71507398cb95cab2e670b654 <41d9673941eebdde62ee73848fcfe4ae1105c979; version=0ca1268e109acf6d71507398cb95cab2e670b654 <ab8336a7e414f018430aa1af3a46944032f7ff96; version=0ca1268e109acf6d71507398cb95cab2e670b654 <bd6c5fe59f374b63173afe5cf0ab38a9a370f2c1; version=0ca1268e109acf6d71507398cb95cab2e670b654 <e124120e89b61a967e40dee6b5e1ecafc45c09d9; version=0ca1268e109acf6d71507398cb95cab2e670b654 <ea2b792330b44b6d7ce671c3e1d59d0c121f7ed1; version=0ca1268e109acf6d71507398cb95cab2e670b654 <f7f566ad7519c7ca3bc9071350002940a2b0e22a; version=2.6.23

Published CVSS scores

4.6TenableCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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

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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