Medium 5.5Published Jul 19, 2026

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

Updated under an hour ago (Oct 27, 2026, 11:00 PM ET)

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Exploited in the last 30 days

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.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: Jul 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 15609d1893020436e1e8ccfd9ded774a96dd17a2 before 33251abb9c9dd62943be76f0427c5527ee39188f; from 15609d1893020436e1e8ccfd9ded774a96dd17a2 before ba09f4baa5bd96c5d26c942defa546a72dbbe5bf; 15609d1893020436e1e8ccfd9ded774a96dd17a2 builds before 6ed16a40b162e9d87d9ac8bed4d7f0e3e807700e; 15609d1893020436e1e8ccfd9ded774a96dd17a2 builds before 0dbf64c502443c08c2e28a77ecbfcc5479d93228; 15609d1893020436e1e8ccfd9ded774a96dd17a2 builds before 2b7a698d5093b548c464828d984f05ced5f3fd2a; from 15609d1893020436e1e8ccfd9ded774a96dd17a2 before ca560f7566df7e2826c2999e959e6b94eb938f76; 15609d1893020436e1e8ccfd9ded774a96dd17a2 builds before 7f705e581ef3e6bb308a121a89adf5237d968204; from 15609d1893020436e1e8ccfd9ded774a96dd17a2 before eee213daa1e1b402eb631bcd1b8c5aa340a6b081	CNA record
linux linux_kernel linux:linux_kernel	from 5.10 before 5.10.258; from 5.11 before 5.15.209; from 5.16 before 6.1.175; from 6.2 before 6.6.142; from 6.7 before 6.12.92; from 6.13 before 6.18.34; from 6.19 before 7.0.11; 7.1; and 3 more ranges	NVD

References

References

https://git.kernel.org/stable/c/33251abb9c9dd62943be76f0427c5527ee39188f	patch
https://git.kernel.org/stable/c/ba09f4baa5bd96c5d26c942defa546a72dbbe5bf	patch
https://git.kernel.org/stable/c/6ed16a40b162e9d87d9ac8bed4d7f0e3e807700e	patch
https://git.kernel.org/stable/c/0dbf64c502443c08c2e28a77ecbfcc5479d93228	patch
https://git.kernel.org/stable/c/2b7a698d5093b548c464828d984f05ced5f3fd2a	patch
https://git.kernel.org/stable/c/ca560f7566df7e2826c2999e959e6b94eb938f76	patch
https://git.kernel.org/stable/c/7f705e581ef3e6bb308a121a89adf5237d968204	patch
https://git.kernel.org/stable/c/eee213daa1e1b402eb631bcd1b8c5aa340a6b081	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.