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NVD / CVE Program· CNA Linux

CVE-2026-64135: hwmon: (pmbus/adm1266) widen blackbox-info buffer to I2C_SMBUS_BLOCK_MAX

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.12% (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 0dbf64c502443c08c2e28a77ecbfcc5479d93228, 2b7a698d5093b548c464828d984f05ced5f3fd2a, 33251abb9c9dd62943be76f0427c5527ee39188f.

Low priority for now. Upgrade to Linux Linux 0dbf64c502443c08c2e28a77ecbfcc5479d93228, 2b7a698d5093b548c464828d984f05ced5f3fd2a, 33251abb9c9dd62943be76f0427c5527ee39188f 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) widen blackbox-info buffer to I2C_SMBUS_BLOCK_MAX adm1266_nvmem_read_blackbox() declares a 5-byte stack buffer and passes it to i2c_smbus_read_block_data() to retrieve the 4-byte BLACKBOX_INFO response. i2c_smbus_read_block_data() does not honour caller buffer sizes -- it memcpy()s data.block[0] bytes from the SMBus transaction (where data.block[0] is the length byte returned by the slave device, up to I2C_SMBUS_BLOCK_MAX = 32): memcpy(values, &data.block[1], data.block[0]); If the device returns any block length above 5, the call overflows the caller's 5-byte stack buffer before the post-call if (ret != 4) return -EIO; check has a chance to reject the response. Widen the local buffer to I2C_SMBUS_BLOCK_MAX so the helper has room for any well-formed SMBus block response, matching the convention used by the other i2c_smbus_read_block_data() callers in this driver.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Jul 19, 2026
Updated
Aug 13, 2026
EPSS
0.1% · 2th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

Get told when this record changes

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  • No public exploit code on record
  • A fix has been released

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  • when exploit code appears or is weaponized
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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
    • 15609d1893020436e1e8ccfd9ded774a96dd17a2 and later · before 33251abb9c9dd62943be76f0427c5527ee39188faffected · git
    • 15609d1893020436e1e8ccfd9ded774a96dd17a2 and later · before ba09f4baa5bd96c5d26c942defa546a72dbbe5bfaffected · git
    • 15609d1893020436e1e8ccfd9ded774a96dd17a2 and later · before 6ed16a40b162e9d87d9ac8bed4d7f0e3e807700eaffected · git
    • 15609d1893020436e1e8ccfd9ded774a96dd17a2 and later · before 0dbf64c502443c08c2e28a77ecbfcc5479d93228affected · git
    • 15609d1893020436e1e8ccfd9ded774a96dd17a2 and later · before 2b7a698d5093b548c464828d984f05ced5f3fd2aaffected · git
    • 15609d1893020436e1e8ccfd9ded774a96dd17a2 and later · before ca560f7566df7e2826c2999e959e6b94eb938f76affected · git
    • 15609d1893020436e1e8ccfd9ded774a96dd17a2 and later · before 7f705e581ef3e6bb308a121a89adf5237d968204affected · git
    • 15609d1893020436e1e8ccfd9ded774a96dd17a2 and later · before eee213daa1e1b402eb631bcd1b8c5aa340a6b081affected · 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-2026-64130Jul 19, 2026 · mm/page_alloc: fix initialization of tags of the huge zero folio with init_on_free
    22Monitor
  • ← EarlierCVE-2026-64132Jul 19, 2026 · ipv6: ioam: refresh hdr pointer before ioam6_event()
    39Monitor
  • Later →CVE-2026-64137Jul 19, 2026 · smb: client: require net admin for CIFS SWN netlink
    31Monitor

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 Linux0dbf64c502443c08c2e28a77ecbfcc5479d93228Vendor (CNA)
Linux Linux2b7a698d5093b548c464828d984f05ced5f3fd2aVendor (CNA)
Linux Linux33251abb9c9dd62943be76f0427c5527ee39188fVendor (CNA)
Linux Linux6ed16a40b162e9d87d9ac8bed4d7f0e3e807700eVendor (CNA)
Linux Linux7f705e581ef3e6bb308a121a89adf5237d968204Vendor (CNA)
Linux Linuxba09f4baa5bd96c5d26c942defa546a72dbbe5bfVendor (CNA)
Linux Linuxca560f7566df7e2826c2999e959e6b94eb938f76Vendor (CNA)
Linux Linuxeee213daa1e1b402eb631bcd1b8c5aa340a6b081Vendor (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.

  • CVE-2026-4318574 days apartksmbd: fix signededness bug in smb_direct_prepare_negotiation()
    39Monitor
  • CVE-2026-5320224 days apartaccel/ivpu: Fix signed integer truncation in IPC receive
    31Monitor
  • CVE-2026-5326724 days apartnetfilter: nft_ct: bail out on template ct in get eval
    31Monitor
  • CVE-2025-38459359 days apartatm: clip: Fix infinite recursive call of clip_push().
    31Monitor
  • CVE-2026-533950 days apartnfsd: fix dead ACL conflict guard in nfsd4_create
    30Monitor
  • CVE-2026-642195 days apartdrm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async
    28Monitor

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

Weakness class (CWE)

CWE-674 · Uncontrolled Recursion

CVSS vector

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

nvd-primary

Attack context

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

ATT&CK techniques

—

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