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CVE Record

CVE-2026-64087: hwmon: (pmbus/adm1266) reject implausible blackbox record_count

In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) reject implausible blackbox record_count adm1266_nvmem_read_blackbox() loops over a record_count that comes straight from byte 3 of the BLACKBOX_INFO response. The destination buffer is data->dev_mem, sized for the nvmem cell's declared 2048 bytes (ADM1266_BLACKBOX_MAX_RECORDS * ADM1266_BLACKBOX_SIZE = 32 * 64). A device that reports a record_count greater than 32 -- whether due to firmware bugs, bus corruption, or a non-responsive slave returning 0xff -- would walk read_buff past the end of the dev_mem allocation on the trailing iterations. Cap record_count at ADM1266_BLACKBOX_MAX_RECORDS (introduced here) before entering the loop and return -EIO on any larger value, so a malformed BLACKBOX_INFO response cannot drive the loop out of bounds.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2026-64087 is a Linux kernel driver bug in the ADM1266 hardware monitoring path. A malformed device response can make the driver process more blackbox records than its allocated buffer can hold, risking kernel memory corruption. Public sources do not provide a CVSS score or exploitation evidence.

Executive priority

Treat as targeted infrastructure hygiene, not a broad internet emergency. Patch during normal kernel maintenance, faster for platforms using ADM1266 monitoring or safety-critical hardware telemetry.

Technical view

adm1266_nvmem_read_blackbox() trusts byte 3 of BLACKBOX_INFO as record_count. Values above 32 can drive reads beyond data->dev_mem, which is sized for 32 records of 64 bytes. The kernel fix rejects implausible counts above ADM1266_BLACKBOX_MAX_RECORDS and returns -EIO.

Likely exposure

Exposure appears limited to Linux systems running affected kernel versions with the hwmon pmbus/adm1266 driver active and interacting with a device or bus condition that returns a malformed BLACKBOX_INFO response.

Exploitation context

The source bundle marks KEV as false and provides no public evidence of active exploitation. The described trigger is a malformed hardware or bus response, including firmware bugs, bus corruption, or a non-responsive slave returning 0xff.

Researcher notes

The record_count source is device-controlled BLACKBOX_INFO byte 3. The sink is data->dev_mem, sized to 2048 bytes. The fix adds ADM1266_BLACKBOX_MAX_RECORDS and returns -EIO for larger values. Impact details and exploitability are not established in the bundle.

Mitigation direction

  • Apply the relevant Linux stable kernel update containing the referenced fix.
  • Prioritize systems using the pmbus/adm1266 hardware monitoring driver.
  • Check distribution vendor advisories for packaged kernel backports.
  • Where patching is delayed, review whether adm1266 driver use is required.

Validation and detection

  • Inventory kernels and compare against vendor fixed releases or referenced commits.
  • Check whether the pmbus/adm1266 driver is built, loaded, or required.
  • Review hardware platforms for ADM1266-related PMBus monitoring use.
  • Confirm updated kernels reject record_count values above 32.
Prepared
Confidence
medium
Sources
10

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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CVE-2026-64087 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
0ADP providers
9Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux15609d1893020436e1e8ccfd9ded774a96dd17a2, 15609d1893020436e1e8ccfd9ded774a96dd17a2, 15609d1893020436e1e8ccfd9ded774a96dd17a2, 15609d1893020436e1e8ccfd9ded774a96dd17a2, 15609d1893020436e1e8ccfd9ded774a96dd17a2, 15609d1893020436e1e8ccfd9ded774a96dd17a2, 15609d1893020436e1e8ccfd9ded774a96dd17a2, 15609d1893020436e1e8ccfd9ded774a96dd17a2unaffected
LinuxLinux5.10, 0, 5.10.258, 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11, 7.1affected
Weakness

CWE details

No CWE listed

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