Linux kernel adm1266 PMBus block transfer buffer overflow
CVE-2026-64086 Published on July 19, 2026
hwmon: (pmbus/adm1266) include PEC byte in pmbus_block_xfer read buffer
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.
Products Associated with CVE-2026-64086
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Affected Versions
Linux:- Version 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and below 397d3f523bfff2f4e3dacf9b1339bd76dc207f78 is affected.
- Version 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and below 472744f69d25a2d5111ad62f1d62579dce2c13c8 is affected.
- Version 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and below 528a9f88e88502d0c2f2052a279415074cd83715 is affected.
- Version 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and below d94ceb16e55b6d8019ab069e357c76ac42f0ffbc is affected.
- Version 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and below bd5be3fa5de6dbf61f1b3cec6b79c2c2f8065694 is affected.
- Version 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and below 2279c342d94eca225bf9f301c8806a05a1c81619 is affected.
- Version 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and below a6c802145a8de0830bca803c6d415f7e9e683624 is affected.
- Version 407dc802a9c0809ca6a48de4b4c63305eb84ef56 and below 487566cb1ccdf3756fdd7bf8d875e612ff3169bb is affected.
- Version 5.10 is affected.
- Before 5.10 is unaffected.
- Version 5.10.258, <= 5.10.* is unaffected.
- Version 5.15.209, <= 5.15.* is unaffected.
- Version 6.1.175, <= 6.1.* is unaffected.
- Version 6.6.142, <= 6.6.* is unaffected.
- Version 6.12.92, <= 6.12.* is unaffected.
- Version 6.18.34, <= 6.18.* is unaffected.
- Version 7.0.11, <= 7.0.* is unaffected.
- Version 7.1, <= * is unaffected.