CVE-2026-64083 — hwmon: (pmbus/adm1266) reject short block-read responses in the GPIO accessors
In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) reject short block-read responses in the GPIO accessors adm1266_gpio_get() and adm1266_gpio_get_multiple() both compose the pin-status word as pins_status = read_buf[0] + (read_buf[1] << 8); right after i2c_smbus_read_block_data(), guarding only against an error return. A well-behaved device returns 2 bytes for GPIO_STATUS/PDIO_STATUS, but the helper happily reports a 0- or 1-byte response too. If the device returns 0 bytes, both read_buf slots are uninitialized stack memory; if it returns 1 byte, read_buf[1] is. The composed value then flows through set_bit() into the caller's *bits in adm1266_gpio_get_multiple(), or into the return value of adm1266_gpio_get(), and ends up in userspace via gpiolib (sysfs and the char-dev ioctls). That leaks a few bits of kernel stack per request on any device whose firmware glitch, bus error, or hostile slave produces a short block-read response. Add the missing length check to both call sites and surface a short response as -EIO.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
version 5.10≥ d98dfad35c38c037b37c4adc99df01da571031a5 and < a7232f68c43ca62f545049b7f5fbfc75137b843b≥ d98dfad35c38c037b37c4adc99df01da571031a5 and < 64fa9328948ddcc0f7f3c23ea1756c126d9dffac≥ d98dfad35c38c037b37c4adc99df01da571031a5 and < eb3cd9bb590460c6127145cb245be925d23f5232≥ d98dfad35c38c037b37c4adc99df01da571031a5 and < ae25cf2ea9ebd06d7ad416647dbdc7b5d0172946≥ d98dfad35c38c037b37c4adc99df01da571031a5 and < a2d1c819348b36fccbbfcf37c5fa7a50a9b4528f≥ d98dfad35c38c037b37c4adc99df01da571031a5 and < c603b6c6840ac0c6285f5eefea0de6242710af21≥ d98dfad35c38c037b37c4adc99df01da571031a5 and < ee4799becf7d2af3778007e22c2e55c4009a49c7 and 1 more≥ d98dfad35c38c037b37c4adc99df01da571031a5 and < fd9196aad9e5a3845cea17de3405ebc700382142 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
version 7.1-rc4≥ 5.10 and < 5.10.258version 7.1-rc3version 7.1-rc2version 7.1-rc1≥ 6.19 and < 7.0.11≥ 6.13 and < 6.18.34≥ 6.7 and < 6.12.92 and 3 more≥ 6.2 and < 6.6.142≥ 5.16 and < 6.1.175≥ 5.11 and < 5.15.209 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.5 | CVSS 3.1 | Medium | 1.8 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- CVSS changed · 5.5
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
8 on the record
- git.kernel.org/stable/c/ae25cf2ea9ebd06d7ad416647dbdc7b5d0172946
- git.kernel.org/stable/c/c603b6c6840ac0c6285f5eefea0de6242710af21
- git.kernel.org/stable/c/fd9196aad9e5a3845cea17de3405ebc700382142
- git.kernel.org/stable/c/a2d1c819348b36fccbbfcf37c5fa7a50a9b4528f
- git.kernel.org/stable/c/ee4799becf7d2af3778007e22c2e55c4009a49c7
- git.kernel.org/stable/c/eb3cd9bb590460c6127145cb245be925d23f5232
- git.kernel.org/stable/c/a7232f68c43ca62f545049b7f5fbfc75137b843b
- git.kernel.org/stable/c/64fa9328948ddcc0f7f3c23ea1756c126d9dffac
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 11h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 11h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-64083 is "hwmon: (pmbus/adm1266) reject short block-read responses in the GPIO accessors", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
Comments
Moderated technical discussion. Read the community guidelines.
No comments yet.
Sign in or create an account to comment and suggest corrections.