CVE-2026-64086: In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) include PEC byte in pmbus_block_xfer read buffer adm1266_pmbus

In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) include PEC byte in pmbus_block_xfer read buffer adm1266_pmbus_bloc

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.

Description from the National Vulnerability Database, published by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

What it means for a small business

Linux is on the computers, phones or browsers your team uses every day. Turn on automatic updates and restart: most of these fixes only take effect after a restart.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.14%, higher than 3% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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