Vulnerability in Linux

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.

EPSS: 0.004 (37.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H.

Affected products

References

Frequently asked questions

What is CVE-2026-64380?
CVE-2026-64380 is a high-severity vulnerability in Linux. CVSS score: 8.2/10. Published 2026-07-25.
How severe is CVE-2026-64380?
High severity. CVSS v3 base score is 8.2 out of 10.