CVE-2026-64512 — ACPI: CPPC: Suppress UBSAN warning caused by field misuse
In the Linux kernel, the following vulnerability has been resolved: ACPI: CPPC: Suppress UBSAN warning caused by field misuse The definition of reg->access_width changes depending on the reg->space_id type. Type ACPI_ADR_SPACE_PLATFORM_COMM uses access_width to indicate the PCC region, which can result in a UBSAN if the value is greater than 4. For example: UBSAN: shift-out-of-bounds in drivers/acpi/cppc_acpi.c:1090:9 shift exponent 32 is too large for 32-bit type 'int' CPU: 61 UID: 0 PID: 1220 Comm: (udev-worker) Not tainted 7.0.10-201.fc44.aarch64 #1 PREEMPT(lazy) Hardware name: To be filled by O.E.M. Call trace: ...(trimming) ubsan_epilogue+0x10/0x48 __ubsan_handle_shift_out_of_bounds+0xdc/0x1e0 cpc_write+0x4d0/0x670 cppc_set_perf+0x18c/0x490 cppc_cpufreq_cpu_init+0x1c8/0x380 [cppc_cpufreq] ... (trimming) Lets fix this by validating the region type, as well as whether access_width has a value. Then since we are returning bit_width directly for ACPI_ADR_SPACE_PLATFORM_COMM, drop the code correcting the size.
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
- No scoring signals.
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.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
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).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- 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 |
≥ 4949affd5288b867cdf115f5b08d6166b2027f87 and < b54c4632946ae42f2b39ed38abd909bbf78cbcc2≥ 01fc53be672acae37e611c80cc0b4f3939584de3 and < e904596ba6dd108534ffa15e3e46b2fe245145e2≥ 1b890ae474d19800a6be1696df7fb4d9a41676e4 and < 2fb80e962029000959f651665baa4838cc92eb99≥ 2f4a4d63a193be6fd530d180bb13c3592052904c and < 37f28bf8f14672dfa395994e41fd778a63f0bf5c≥ 2f4a4d63a193be6fd530d180bb13c3592052904c and < f29dc6132d4968e39d8fa575d1a12e2c718ce57b≥ 2f4a4d63a193be6fd530d180bb13c3592052904c and < dc066bd13c860bb27d6ace511210e18b8064c1d9≥ 2f4a4d63a193be6fd530d180bb13c3592052904c and < 1b1acf2dada0cc3931bb2cb9ff8832edfbee46a1version 6cb6b12b78dcd8867a3fdbb1b6d0ed1df2b208d1 and 5 more≥ 5.15.154 and < 5.15.155≥ 6.1.90 and < 6.1.178≥ 6.6.30 and < 6.6.145≥ 6.8.9 and < 6.9version 6.9 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- 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
7 on the record
- git.kernel.org/stable/c/f29dc6132d4968e39d8fa575d1a12e2c718ce57b
- git.kernel.org/stable/c/1b1acf2dada0cc3931bb2cb9ff8832edfbee46a1
- git.kernel.org/stable/c/2fb80e962029000959f651665baa4838cc92eb99
- git.kernel.org/stable/c/b54c4632946ae42f2b39ed38abd909bbf78cbcc2
- git.kernel.org/stable/c/e904596ba6dd108534ffa15e3e46b2fe245145e2
- git.kernel.org/stable/c/dc066bd13c860bb27d6ace511210e18b8064c1d9
- git.kernel.org/stable/c/37f28bf8f14672dfa395994e41fd778a63f0bf5c
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 13h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 13h
- 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 CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- 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-2026-64512 is "ACPI: CPPC: Suppress UBSAN warning caused by field misuse", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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