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VulnerabilityPublished Updated

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

Source GCVE Database

0

Not known to be exploited · CVSS 5.5 Medium.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
5.5Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 19 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

AI-suggested

A fix has been implemented in the Linux kernel by increasing the buffer size to I2C_SMBUS_BLOCK_MAX to prevent overflow. Users should update to a kernel version that includes this patch. Since this is a kernel-level vulnerability, applying the official kernel update is the recommended remediation. No additional mitigations are indicated.

Description

A vulnerability in the Linux kernel's hwmon driver for pmbus/adm1266 was resolved by widening a stack buffer used to read SMBus block data. The original code allocated a 5-byte buffer but the SMBus protocol can return up to 32 bytes, causing a potential stack buffer overflow. This overflow occurs before a length check can reject oversized responses. The fix increases the buffer size to the maximum SMBus block size to prevent overflow.

References

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