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NVD / CVE Program· CNA Linux

CVE-2026-64086: hwmon: (pmbus/adm1266) include PEC byte in pmbus_block_xfer read buffer

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.13% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 2279c342d94eca225bf9f301c8806a05a1c81619, 397d3f523bfff2f4e3dacf9b1339bd76dc207f78, 472744f69d25a2d5111ad62f1d62579dce2c13c8.

Low priority for now. Upgrade to Linux Linux 2279c342d94eca225bf9f301c8806a05a1c81619, 397d3f523bfff2f4e3dacf9b1339bd76dc207f78, 472744f69d25a2d5111ad62f1d62579dce2c13c8 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) include PEC byte in pmbus_block_xfer read buffer adm1266_pmbus_block_xfer() sets up the read transaction with .buf = data->read_buf, .len = ADM1266_PMBUS_BLOCK_MAX + 2, but read_buf in struct adm1266_data is declared as u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1]; For a max-length block response (length byte = 255 + up to 1 PEC byte), the i2c controller is told to write 257 bytes into a 256-byte buffer, putting one byte past the end of read_buf. The same response also makes the subsequent PEC compare if (crc != msgs[1].buf[msgs[1].buf[0] + 1]) read a byte beyond the array. Bump the read_buf declaration to ADM1266_PMBUS_BLOCK_MAX + 2 so the buffer can hold the length byte, up to 255 payload bytes, and the PEC byte the i2c_msg length already accounts for.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Jul 19, 2026
Updated
Sep 3, 2026
EPSS
0.1% · 3th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel5.10 and later · before 5.10.258
  • linux linux kernel5.11 and later · before 5.15.209
  • linux linux kernel5.16 and later · before 6.1.175
  • linux linux kernel6.2 and later · before 6.6.142
  • linux linux kernel6.7 and later · before 6.12.92
  • linux linux kernel6.13 and later · before 6.18.34
  • linux linux kernel6.19 and later · before 7.0.11
  • linux linux kernel7.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.10affected
    • 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and later · before 397d3f523bfff2f4e3dacf9b1339bd76dc207f78affected · git
    • 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and later · before 472744f69d25a2d5111ad62f1d62579dce2c13c8affected · git
    • 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and later · before 528a9f88e88502d0c2f2052a279415074cd83715affected · git
    • 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and later · before d94ceb16e55b6d8019ab069e357c76ac42f0ffbcaffected · git
    • 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and later · before bd5be3fa5de6dbf61f1b3cec6b79c2c2f8065694affected · git
    • 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and later · before 2279c342d94eca225bf9f301c8806a05a1c81619affected · git
    • 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and later · before a6c802145a8de0830bca803c6d415f7e9e683624affected · git
    • 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and later · before 487566cb1ccdf3756fdd7bf8d875e612ff3169bbaffected · git
    • before 5.10not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.94-16.12.94-1
Debian:14linuxbefore 7.0.12-17.0.12-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-64084Jul 19, 2026 · hwmon: (pmbus/adm1266) cap PDIO scan in get_multiple at ADM1266_PDIO_NR
    31Monitor
  • ← EarlierCVE-2026-64085Jul 19, 2026 · hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer
    31Monitor
  • Later →CVE-2026-64087Jul 19, 2026 · hwmon: (pmbus/adm1266) reject implausible blackbox record_count
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux2279c342d94eca225bf9f301c8806a05a1c81619Vendor (CNA)
Linux Linux397d3f523bfff2f4e3dacf9b1339bd76dc207f78Vendor (CNA)
Linux Linux472744f69d25a2d5111ad62f1d62579dce2c13c8Vendor (CNA)
Linux Linux487566cb1ccdf3756fdd7bf8d875e612ff3169bbVendor (CNA)
Linux Linux528a9f88e88502d0c2f2052a279415074cd83715Vendor (CNA)
Linux Linuxa6c802145a8de0830bca803c6d415f7e9e683624Vendor (CNA)
Linux Linuxbd5be3fa5de6dbf61f1b3cec6b79c2c2f8065694Vendor (CNA)
Linux Linuxd94ceb16e55b6d8019ab069e357c76ac42f0ffbcVendor (CNA)
debian:linux6.1.176-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records