CVE-2026-63964

Kernel crash via missing firmware record header

Published Jul 19, 2026 · Updated Jul 19, 2026

A NULL pointer dereference in affected Linux Kernel releases allows local users with root access to crash the kernel via crafted CCG firmware. The do_flash function accepts a .cyacd image without a colon record header, treats the NULL search result as preceding the buffer end, and calls strnchr from address 1 with an oversized length. Exploitation requires control of a file under /lib/firmware and write access to the UCSI CCG do_flash sysfs attribute; success causes a kernel oops and service interruption.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

A NULL pointer dereference in affected Linux Kernel releases allows local users with root access to crash the kernel via crafted CCG firmware. The do_flash function accepts a .cyacd image without a colon record header, treats the NULL search result as preceding the buffer end, and calls strnchr from address 1 with an oversized length. Exploitation requires control of a file under /lib/firmware and write access to the UCSI CCG do_flash sysfs attribute; success causes a kernel oops and service interruption.

The record

CVE
CVE-2026-63964
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
Attack vector
local
Privileges
admin

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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <5.10.259
  2. Affected versionversion=0 <5.15.210
  3. Affected versionversion=0 <6.1.176
  4. Affected versionversion=0 <6.12.93
  5. Affected versionversion=0 <6.18.35
  6. Affected versionversion=0 <6.6.143
  7. Affected versionversion=0 <7.0.12
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2f395ca1263bd181995eb829f5943a83a20db213
  9. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3f432b8203066c26770fe6ea591361f10021dd6b
  10. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6526f8684f72391138353642af908803ba70795e
  11. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a38ed87818b2419090fb1a6338ddce6842b65dfa
  12. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b41dfc033fe594e152648050e95b9489cd53e9e3
  13. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb
  14. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c8460de584fe5415d212cfdd127d4db90835a450
  15. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d7486952bf74e546ee3748fb14b2d07881fa6273

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0 <5.10.259; version=0 <5.15.210; version=0 <6.1.176; version=0 <6.12.93; version=0 <6.18.35; version=0 <6.6.143; version=0 <7.0.12; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2f395ca1263bd181995eb829f5943a83a20db213; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3f432b8203066c26770fe6ea591361f10021dd6b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6526f8684f72391138353642af908803ba70795e; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a38ed87818b2419090fb1a6338ddce6842b65dfa; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b41dfc033fe594e152648050e95b9489cd53e9e3; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c8460de584fe5415d212cfdd127d4db90835a450; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d7486952bf74e546ee3748fb14b2d07881fa6273

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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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