CVE-2018-12127: Infoleak
Last updated 25 August 2025
Other sources
Microarchitectural Load Port Data Sampling (MLPDS): Load ports on some microprocessors utilizing speculative execution may allow an authenticated user to potentially enable information disclosure via a side channel with local access. A list of impacted products can be found here: https://www.intel.com/content/dam/www/public/us/en/documents/corporate-information/SA00233-microcode-update-guidance05132019.pdf
— Launchpad
Microcode. Multiple information disclosure issues were addressed partially by updating the microcode and changing the OS scheduler to isolate the system from web content running in the browser. To completely address these issues, there are additional opt-in mitigations to disable hyper threading and enable microcode-based mitigations for all processes by default. Details of the mitigations can be found at https://support.apple.com/kb/HT210107.
Microprocessors use ‘load ports’ to perform load operations from memory or IO. During a load operation, the load port receives data from the memory or IO subsystem and then provides the data to the CPU registers and operations in the CPU’s pipelines.
In some implementations, the writeback data bus within each load port can retain data values from older load operations until newer load operations overwrite that data
MLPDS can reveal stale load port data to malicious actors when:
- A faulting/assisting SSE/AVX/AVX-512 loads that are more than 64 bits in size - A faulting/assisting load which spans a 64-byte boundary.
In the above cases, the load operation speculatively provides stale data values from the internal data structures to dependent operations. Speculatively forwarding this data does not end up modifying program execution, but this can be used as a widget to speculatively infer the contents of a victim processes data value through timing access to the load port.
Additional information: https://access.redhat.com/security/vulnerabilities/mds
Upstream fixes: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa4bff165070dc40a3de35b78e4f8da8e8d85ec5
Intel Advisory: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00233.html
— Red Hat
Credit
Affected Software
Remediation
Event History
Peer vulnerabilities
Found alongside the following vulnerabilities.
- CVE-2019-8603
- CVE-2019-8635
- CVE-2019-8590
- CVE-2019-8640
- CVE-2019-2102
- CVE-2019-8592
- CVE-2019-8585
- CVE-2019-8582
- CVE-2019-8589
- CVE-2019-8560
- CVE-2019-8634
- CVE-2019-8616
- CVE-2019-8629
- CVE-2018-4456
- CVE-2019-8606
- CVE-2019-8633
- CVE-2019-8525
- CVE-2019-8547
- CVE-2019-8576
- CVE-2019-8591
- CVE-2019-8573
- CVE-2019-8631
- CVE-2018-12126
- CVE-2018-12127
- CVE-2018-12130
- CVE-2019-11091
- CVE-2019-8604
- CVE-2019-8577
- CVE-2019-8600
- CVE-2019-8598
- CVE-2019-8602
- CVE-2019-8568
- CVE-2019-8574
- CVE-2019-8569
- CVE-2019-6237
- CVE-2019-8571
- CVE-2019-8583
- CVE-2019-8584
- CVE-2019-8586
- CVE-2019-8587
- CVE-2019-8594
- CVE-2019-8595
- CVE-2019-8596
- CVE-2019-8597
- CVE-2019-8601
- CVE-2019-8608
- CVE-2019-8609
- CVE-2019-8610
- CVE-2019-8611
- CVE-2019-8615
- CVE-2019-8619
- CVE-2019-8622
- CVE-2019-8623
- CVE-2019-8628
- CVE-2019-8607
- CVE-2019-8612
Frequently Asked Questions
What is the severity of CVE-2018-12127?
CVE-2018-12127 has a medium severity rating due to potential information disclosure through a side channel.
How do I fix CVE-2018-12127?
To mitigate CVE-2018-12127, ensure your system firmware and operating system are updated to the latest secure versions provided by your vendor.
Which systems are affected by CVE-2018-12127?
CVE-2018-12127 affects certain versions of macOS Mojave, macOS High Sierra, macOS Sierra, and various distributions of Linux with Intel microprocessors.
What type of vulnerability is CVE-2018-12127?
CVE-2018-12127 is a microarchitectural vulnerability related to speculative execution, specifically Microarchitectural Load Port Data Sampling (MLPDS).
Can CVE-2018-12127 be exploited locally?
Yes, CVE-2018-12127 can potentially be exploited by an authenticated user with local access to the system.