What is CVE-2026-64004?

CVE-2026-64004 is a unscored severity Linux kernel vulnerability, affecting Linux kernel versions from 3.4 onward and patched in 5.10.259, 5.15.210, 6.1.176 and others. CVE-2026-64004 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-64004?

CVE-2026-64004 has a CVSS score of pending NVD analysis out of 10, rated awaiting scoring severity.

Is there a patch available for CVE-2026-64004?

Yes, CVE-2026-64004 has been patched. Fixed versions include 5.10.259, 5.15.210, 6.1.176 and others. If you are running Linux kernel 3.4 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-64004 actively exploited?

CVE-2026-64004 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-64004

In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix locking in .getsockopt Mirror iucv_sock_setsockopt() and wrap the whole switch in lock_sock()/release_sock(). The pre-existing SO_MSGLIMIT-only lock becomes redundant and is removed. Any AF_IUCV HIPER user can potentially crash the kernel by racing recvmsg() with getsockopt(SO_MSGSIZE): the SO_MSGSIZE arm dereferences iucv->hs_dev->mtu after iucv_sock_close() (called from the racing recvmsg()) has set hs_dev to NULL, producing a NULL pointer dereference oops.

Package Linux Kernel

Published 2026-07-19

Last modified 2026-07-19

Patch available

Yes

Affected versions

Linux kernel versions 3.4 and later are affected. Fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12, 7.1 and their respective stable series.

Affected from

≥ 3.4

Fixed in

✓ 5.10.259 5.10.x ✓ 5.15.210 5.15.x ✓ 6.1.176 6.1.x ✓ 6.6.143 6.6.x ✓ 6.12.93 6.12.x ✓ 6.18.35 6.18.x ✓ 7.0.12 7.0.x ✓ 7.1

References

8 total

Showing 5 of 8 references View all on NVD

Frequently asked questions

What is CVE-2026-64004?

CVE-2026-64004 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 3.4 onward and has been patched in 5.10.259, 5.15.210, 6.1.176 and others. CVE-2026-64004 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
Is there a patch available for CVE-2026-64004?

Yes — CVE-2026-64004 has been patched. Fixed versions include 5.10.259, 5.15.210, 6.1.176 and others. If you are running Linux kernel 3.4 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-64004 actively exploited?

No — CVE-2026-64004 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.