What is CVE-2026-64263?

CVE-2026-64263 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 6.16 onward and patched in 6.18.39, 7.1.4 and 7.2. CVE-2026-64263 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-64263?

CVE-2026-64263 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-64263?

Yes, CVE-2026-64263 has been patched. Fixed versions include 6.18.39, 7.1.4 and 7.2. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-64263 actively exploited?

CVE-2026-64263 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-64263

Medium

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.

Package Linux Kernel

Published 2026-07-25

Last modified 2026-08-17

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 6.16 and later are affected. Fixed in 6.18.39, 7.1.4, 7.2 and their respective stable series.

Affected from

≥ 6.16

Fixed in

✓ 6.18.39 6.18.x ✓ 7.1.4 7.1.x ✓ 7.2

References

3 total

Kernel Git
https://git.kernel.org/stable/c/198f45eeb9f78b2a2d6d8be95e4e43468eb2c6bc

Patch
Kernel Git
https://git.kernel.org/stable/c/50f3e03db823cabc41fe35c27d77c2bdb112baad

Patch
Kernel Git
https://git.kernel.org/stable/c/e8afc85acdf329361b2d8df2ad9b52364686235f

Patch

Details

CVE ID CVE-2026-64263

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-07-25

Modified 2026-08-17

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-64263?

CVE-2026-64263 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.16 onward and has been patched in 6.18.39, 7.1.4 and 7.2. CVE-2026-64263 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-64263?

CVE-2026-64263 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-64263?

Yes. CVE-2026-64263 has been patched. Fixed versions include 6.18.39, 7.1.4 and 7.2. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-64263 actively exploited?

No. CVE-2026-64263 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.