CVE-2026-64477x86,fs/resctrl: Prevent out-of-bounds access while offlining CPU when SNC enabled
- 7.1HighCVSS base score
- 0.18%Exploitation in 30 daysEPSS · top 93% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: x86,fs/resctrl: Prevent out-of-bounds access while offlining CPU when SNC enabled The architecture updates the cpu_mask in a domain's header to track which online CPUs are associated with the domain. When this mask becomes empty the architecture initiates offline of the domain that includes calling on resctrl fs to offline the domain. If it is a monitoring domain in which LLC occupancy is tracked resctrl fs forces the limbo handler to clear all busy RMID state associated with the domain. The limbo handler always reads the current event value associated with a busy RMID irrespective of it being checked as part of regular "is it still busy" check or whether it will be forced released anyway. When reading an RMID on a system with SNC enabled the "logical RMID" is converted to the "physical RMID" and this conversion requires the NUMA node ID of the resctrl monitoring domain that is in turn determined by querying the NUMA node ID of any CPU belonging to the monitoring domain. When the monitoring domain is going offline its cpu_mask is empty causing the NUMA node ID query via cpu_to_node() to be done with "nr_cpu_ids" as argument resulting in an out-of-bounds access. Refactor the limbo handler to skip reading the RMID when the RMID will just be forced to no longer be dirty in the domain anyway. Add a safety check to the architecture's RMID reader to protect against this scenario.
Timeline
ID reserved
By Linux
- 6 days later
· 6 days later
Published
- 23 days later
· 23 days later
Record updated
- 3 months later
· 3 months later
First scored
High 7.1
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | High7.1 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.18% · top 93% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.
Affected products
- affected e13db55b5a0d447dea63cde772c1078405bbbf96 – < ebc300b7ee0c669fa76a7a8858298ff32e296103
- affected e13db55b5a0d447dea63cde772c1078405bbbf96 – < be1567992417dc92133e74126de7a6066c825ac9
- affected e13db55b5a0d447dea63cde772c1078405bbbf96 – < 58c5ec23b1a238eb75cb0aba6f69d8f9e68ef0b2
- affected e13db55b5a0d447dea63cde772c1078405bbbf96 – < fc16126cc11d9f507130bf84ab137ee0938c900e
- affected 6.11
- unaffected < 6.11
- unaffected 6.12.96 – ≤ 6.12.*
- unaffected 6.18.39 – ≤ 6.18.*
- unaffected 7.1.4 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References4
- https://git.kernel.org/stable/c/ebc300b7ee0c669fa76a7a8858298ff32e296103 (opens in a new tab)
- https://git.kernel.org/stable/c/be1567992417dc92133e74126de7a6066c825ac9 (opens in a new tab)
- https://git.kernel.org/stable/c/58c5ec23b1a238eb75cb0aba6f69d8f9e68ef0b2 (opens in a new tab)
- https://git.kernel.org/stable/c/fc16126cc11d9f507130bf84ab137ee0938c900e (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-48821 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-64477)Record last updated .