Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-64085
Linux Linux — hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U H H H 7.8 .0018 6.4 —
AFFECTED
Product Versions Fixed
Linux 407dc802a9c0809ca6a48de4b4c63305eb84ef56 – —
Linux 5.10 – 5.10.258
TIMELINE
Jul 19 Reserved by Linux
Jul 19 Published (CNA: Linux)
Sep 3 ENRICHED — CVE-2026-64085 (Linux). Received CVSS 7.8 and CPE data from NVD.
Description
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer
adm1266_pmbus_block_xfer() copies the device-supplied block payload
into the caller-provided buffer using the device-supplied length:
memcpy(data_r, &msgs[1].buf[1], msgs[1].buf[0]);
The helper does not know how large data_r is and trusts the device to
return at most one record's worth of bytes. adm1266_nvmem_read_blackbox()
violates that contract: it advances read_buff inside data->dev_mem in
ADM1266_BLACKBOX_SIZE (64-byte) strides while the helper is willing to
write up to ADM1266_PMBUS_BLOCK_MAX (255) bytes. A device that returns
more than 64 bytes on the trailing record (read_buff offset 1984 in
the 2048-byte dev_mem allocation) overflows dev_mem by up to 191 bytes
before the post-call
if (ret != ADM1266_BLACKBOX_SIZE)
return -EIO;
can reject the response.
Contain the fix in the caller without changing the helper signature:
read each record into a 255-byte local bounce buffer that matches the
helper's maximum output, validate the returned length, and only then
copy exactly ADM1266_BLACKBOX_SIZE bytes into the dev_mem slot.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| July 19, 2026 | Reserved | Reserved by Linux |
| July 19, 2026 | Published | Published (CNA: Linux) |
| September 3, 2026 | ENRICHED | ENRICHED — CVE-2026-64085 (Linux). Received CVSS 7.8 and CPE data from NVD. |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| Linux | Linux | — | 407dc802a9c0809ca6a48de4b4c63305eb84ef56 | — |
| Linux | Linux | — | 5.10 | 5.10.258 |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-64085 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
