Answer in brief
CVE-2026-64036 records a Unknown severity vulnerability in cgroup/rstat: validate cpu before css_rstat_cpu() access. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=a319185be9f5ad13c2a296d448ac52ffe45d194c <6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6 || >=a319185be9f5ad13c2a296d448ac52ffe45d194c <fd2bd9fa7700ddf28296486b2598cff2f80cc819 || >=a319185be9f5ad13c2a296d448ac52ffe45d194c <8817005efbdfdf5d4e4814cb5dc52b53d12917d7 | 6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6, fd2bd9fa7700ddf28296486b2598cff2f80cc819, 8817005efbdfdf5d4e4814cb5dc52b53d12917d7 |
| Linux/Linuxgeneric | 6.1 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-64036 records a Unknown severity vulnerability in cgroup/rstat: validate cpu before css_rstat_cpu() access. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=a319185be9f5ad13c2a296d448ac52ffe45d194c <6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6 || >=a319185be9f5ad13c2a296d448ac52ffe45d194c <fd2bd9fa7700ddf28296486b2598cff2f80cc819 || >=a319185be9f5ad13c2a296d448ac52ffe45d194c <8817005efbdfdf5d4e4814cb5dc52b53d12917d7 | 6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6, fd2bd9fa7700ddf28296486b2598cff2f80cc819, 8817005efbdfdf5d4e4814cb5dc52b53d12917d7 |
| Linux/Linuxgeneric | 6.1 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.