Answer in brief
CVE-2026-64263 records a Medium severity (CVSS 5.5) vulnerability in fuse-uring: fix moving cancelled entry to ent_in_userspace list. 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 | >=4fea593e625cd50d4d11be227007849b12f17bfb <50f3e03db823cabc41fe35c27d77c2bdb112baad || >=4fea593e625cd50d4d11be227007849b12f17bfb <e8afc85acdf329361b2d8df2ad9b52364686235f || >=4fea593e625cd50d4d11be227007849b12f17bfb <198f45eeb9f78b2a2d6d8be95e4e43468eb2c6bc | 50f3e03db823cabc41fe35c27d77c2bdb112baad, e8afc85acdf329361b2d8df2ad9b52364686235f, 198f45eeb9f78b2a2d6d8be95e4e43468eb2c6bc |
| Linux/Linuxgeneric | 6.16 | 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-uring: fix moving cancelled entry to ent_in_userspace list fuse_uring_cancel() moves entries that are available (these have no reqs attached) to the ent_in_userspace list. ent_list_request_expired() checks the first entry on ent_in_userspace and dereferences ent->fuse_req unconditionally, which will crash on a cancelled entry that was moved to this list. Fix this by freeing the entry and dropping queue_refs directly in fuse_uring_cancel(). This is safe because cancel is the cancel handler itself - after io_uring_cmd_done(), no more cancels will be dispatched for this command, and teardown serializes with cancel via queue->lock. Since cancel now decrements queue_refs, fuse_uring_abort() must no longer gate fuse_uring_abort_end_requests() on queue_refs > 0, as cancelled entries may have already dropped queue_refs while requests are still queued. Remove the gate so abort always flushes requests and stops queues.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-64263 records a Medium severity (CVSS 5.5) vulnerability in fuse-uring: fix moving cancelled entry to ent_in_userspace list. 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 | >=4fea593e625cd50d4d11be227007849b12f17bfb <50f3e03db823cabc41fe35c27d77c2bdb112baad || >=4fea593e625cd50d4d11be227007849b12f17bfb <e8afc85acdf329361b2d8df2ad9b52364686235f || >=4fea593e625cd50d4d11be227007849b12f17bfb <198f45eeb9f78b2a2d6d8be95e4e43468eb2c6bc | 50f3e03db823cabc41fe35c27d77c2bdb112baad, e8afc85acdf329361b2d8df2ad9b52364686235f, 198f45eeb9f78b2a2d6d8be95e4e43468eb2c6bc |
| Linux/Linuxgeneric | 6.16 | 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-uring: fix moving cancelled entry to ent_in_userspace list fuse_uring_cancel() moves entries that are available (these have no reqs attached) to the ent_in_userspace list. ent_list_request_expired() checks the first entry on ent_in_userspace and dereferences ent->fuse_req unconditionally, which will crash on a cancelled entry that was moved to this list. Fix this by freeing the entry and dropping queue_refs directly in fuse_uring_cancel(). This is safe because cancel is the cancel handler itself - after io_uring_cmd_done(), no more cancels will be dispatched for this command, and teardown serializes with cancel via queue->lock. Since cancel now decrements queue_refs, fuse_uring_abort() must no longer gate fuse_uring_abort_end_requests() on queue_refs > 0, as cancelled entries may have already dropped queue_refs while requests are still queued. Remove the gate so abort always flushes requests and stops queues.
Quoted source text, attributed separately from HOL analysis.