CVE-2026-64036cgroup/rstat: validate cpu before css_rstat_cpu() access
- 7.8HighCVSS base score
- 0.13%Exploitation in 30 daysEPSS · top 97% 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: cgroup/rstat: validate cpu before css_rstat_cpu() access css_rstat_updated() is exposed as a BPF kfunc and accepts a caller-provided cpu argument. The function uses cpu for per-cpu rstat lookups without checking whether it refers to a valid possible CPU. A BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an invalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu == 0x7fffffff triggers: UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9 index 2147483647 is out of range for type 'long unsigned int [64]' Call Trace: css_rstat_updated bpf_iter_run_prog cgroup_iter_seq_show bpf_seq_read Add cpu validation to the BPF-facing css_rstat_updated() kfunc and move the common implementation to __css_rstat_updated() for in-kernel callers.
Timeline
ID reserved
By Linux
Published
- 3 months later
· 3 months later
Record updated
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 |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.13% · top 97% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected a319185be9f5ad13c2a296d448ac52ffe45d194c – < ee5afb74688aa6f1f16d8c7e7b6bfaf803fb62fc
- affected a319185be9f5ad13c2a296d448ac52ffe45d194c – < b28b862b07257219755d0b0a7fbe5d23b7c9ea91
- affected a319185be9f5ad13c2a296d448ac52ffe45d194c – < 3d595affbe00a2e8bf43b9f2947a8efcdc1c059e
- affected a319185be9f5ad13c2a296d448ac52ffe45d194c – < 6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6
- affected a319185be9f5ad13c2a296d448ac52ffe45d194c – < fd2bd9fa7700ddf28296486b2598cff2f80cc819
- affected a319185be9f5ad13c2a296d448ac52ffe45d194c – < 8817005efbdfdf5d4e4814cb5dc52b53d12917d7
- affected 6.1
- unaffected < 6.1
- unaffected 6.1.191 – ≤ 6.1.*
- unaffected 6.6.160 – ≤ 6.6.*
- unaffected 6.12.114 – ≤ 6.12.*
- unaffected 6.18.34 – ≤ 6.18.*
- unaffected 7.0.11 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References6
- https://git.kernel.org/stable/c/ee5afb74688aa6f1f16d8c7e7b6bfaf803fb62fc (opens in a new tab)
- https://git.kernel.org/stable/c/b28b862b07257219755d0b0a7fbe5d23b7c9ea91 (opens in a new tab)
- https://git.kernel.org/stable/c/3d595affbe00a2e8bf43b9f2947a8efcdc1c059e (opens in a new tab)
- https://git.kernel.org/stable/c/6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6 (opens in a new tab)
- https://git.kernel.org/stable/c/fd2bd9fa7700ddf28296486b2598cff2f80cc819 (opens in a new tab)
- https://git.kernel.org/stable/c/8817005efbdfdf5d4e4814cb5dc52b53d12917d7 (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-2026-45609 (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-2026-64036)Record last updated .