Answer in brief
CVE-2026-64267 records a Medium severity (CVSS 5.5) vulnerability in fuse: avoid 32-bit prune notification count wrap. 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.
CVSS is 5.5. 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.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=3f29d59e92a96d843c2ff10ebfed92ac26878658 <6e2d84fdeac05bfd858e84a76353fdb84f23a43e || >=3f29d59e92a96d843c2ff10ebfed92ac26878658 <c78c4b242299bc581e4987e5c2786c6f4760c516 || >=3f29d59e92a96d843c2ff10ebfed92ac26878658 <54243797cedf55447b4c5d560e8cd709900061ae | 6e2d84fdeac05bfd858e84a76353fdb84f23a43e, c78c4b242299bc581e4987e5c2786c6f4760c516, 54243797cedf55447b4c5d560e8cd709900061ae |
| Linux/Linuxgeneric | 6.18 | Not reported |
Published upstream
Jul 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 12, 2026
In the Linux kernel, the following vulnerability has been resolved: fuse: avoid 32-bit prune notification count wrap FUSE_NOTIFY_PRUNE validates the nodeid payload length with: size - sizeof(outarg) != outarg.count * sizeof(u64) On 32-bit kernels, size_t is also 32 bits, so the daemon-controlled count multiplication can wrap. A prune notification with count 0x20000000 and no nodeid payload passes the check, enters the copy loop, and asks the device copy path to read nodeids that are not present in the userspace write buffer. In QEMU this reaches the fuse_copy_fill() BUG_ON(!err) path. Validate the payload length with array_size() instead. That accepts exactly the same valid messages, but avoids wrapping arithmetic before the copy loop consumes the count.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-64267 records a Medium severity (CVSS 5.5) vulnerability in fuse: avoid 32-bit prune notification count wrap. 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.
CVSS is 5.5. 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.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=3f29d59e92a96d843c2ff10ebfed92ac26878658 <6e2d84fdeac05bfd858e84a76353fdb84f23a43e || >=3f29d59e92a96d843c2ff10ebfed92ac26878658 <c78c4b242299bc581e4987e5c2786c6f4760c516 || >=3f29d59e92a96d843c2ff10ebfed92ac26878658 <54243797cedf55447b4c5d560e8cd709900061ae | 6e2d84fdeac05bfd858e84a76353fdb84f23a43e, c78c4b242299bc581e4987e5c2786c6f4760c516, 54243797cedf55447b4c5d560e8cd709900061ae |
| Linux/Linuxgeneric | 6.18 | Not reported |
Published upstream
Jul 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 12, 2026
In the Linux kernel, the following vulnerability has been resolved: fuse: avoid 32-bit prune notification count wrap FUSE_NOTIFY_PRUNE validates the nodeid payload length with: size - sizeof(outarg) != outarg.count * sizeof(u64) On 32-bit kernels, size_t is also 32 bits, so the daemon-controlled count multiplication can wrap. A prune notification with count 0x20000000 and no nodeid payload passes the check, enters the copy loop, and asks the device copy path to read nodeids that are not present in the userspace write buffer. In QEMU this reaches the fuse_copy_fill() BUG_ON(!err) path. Validate the payload length with array_size() instead. That accepts exactly the same valid messages, but avoids wrapping arithmetic before the copy loop consumes the count.
Quoted source text, attributed separately from HOL analysis.