CVE-2026-64135: Linux kernel · hwmon: (pmbus/adm1266) widen blackbox-info buffer to I2C_SMBUS_BLOCK_MAX
Source GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 26 Oct 2026, 13:47 UTC
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
- nvd.nist.gov/vuln/detail/CVE-2026-64135 (opens in a new tab)
- git.kernel.org/stable/c/0dbf64c502443c08c2e28a77ecbfcc5479d93228 (opens in a new tab)
- git.kernel.org/stable/c/2b7a698d5093b548c464828d984f05ced5f3fd2a (opens in a new tab)
- git.kernel.org/stable/c/33251abb9c9dd62943be76f0427c5527ee39188f (opens in a new tab)
- git.kernel.org/stable/c/6ed16a40b162e9d87d9ac8bed4d7f0e3e807700e (opens in a new tab)
- git.kernel.org/stable/c/7f705e581ef3e6bb308a121a89adf5237d968204 (opens in a new tab)
- git.kernel.org/stable/c/ba09f4baa5bd96c5d26c942defa546a72dbbe5bf (opens in a new tab)
- git.kernel.org/stable/c/ca560f7566df7e2826c2999e959e6b94eb938f76 (opens in a new tab)
- git.kernel.org/stable/c/eee213daa1e1b402eb631bcd1b8c5aa340a6b081 (opens in a new tab)