What is CVE-2026-64380?

CVE-2026-64380 is a unscored severity Linux kernel vulnerability, affecting Linux kernel versions from 5.7 onward and patched in 5.10.261, 5.15.212, 6.1.178 and others. CVE-2026-64380 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-64380?

CVE-2026-64380 has a CVSS score of pending NVD analysis out of 10, rated awaiting scoring severity.

Is there a patch available for CVE-2026-64380?

Yes, CVE-2026-64380 has been patched. Fixed versions include 5.10.261, 5.15.212, 6.1.178 and others. If you are running Linux kernel 5.7 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-64380 actively exploited?

CVE-2026-64380 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-64380

In the Linux kernel, the following vulnerability has been resolved: smb: client: harden POSIX SID length parsing posix_info_sid_size() reads sid[1] to obtain the subauthority count, but its existing boundary check still accepts buffers with only one remaining byte. Require two bytes before reading sid[1] so all client paths that reuse the helper reject truncated POSIX SIDs safely.

Package Linux Kernel

Published 2026-07-25

Last modified 2026-07-25

Patch available

Yes

Affected versions

Linux kernel versions 5.7 and later are affected. Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2-rc2 and their respective stable series.

Affected from

≥ 5.7

Fixed in

✓ 5.10.261 5.10.x ✓ 5.15.212 5.15.x ✓ 6.1.178 6.1.x ✓ 6.6.145 6.6.x ✓ 6.12.96 6.12.x ✓ 6.18.39 6.18.x ✓ 7.1.4 7.1.x ✓ 7.2-rc2

References

8 total

Showing 5 of 8 references View all on NVD

Frequently asked questions

What is CVE-2026-64380?

CVE-2026-64380 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.7 onward and has been patched in 5.10.261, 5.15.212, 6.1.178 and others. CVE-2026-64380 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
Is there a patch available for CVE-2026-64380?

Yes. CVE-2026-64380 has been patched. Fixed versions include 5.10.261, 5.15.212, 6.1.178 and others. If you are running Linux kernel 5.7 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-64380 actively exploited?

No. CVE-2026-64380 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.