Vulnerability in Linux
CVE-2026-64257
In the Linux kernel, the following vulnerability has been resolved: smb: client: reject overlapping data areas in SMB2 responses Commit 53b7c271f06b ("smb: client: restrict implied bcc[0] exemption to responses without data area") restricted the implied bcc[0] length exception to responses without a data area. However, the overlap handling in __smb2_calc_size() clears data_length, which can make an invalid response appear to have no data area and so qualify for the exception. Track data area overlap separately and reject such responses before applying the length compatibility exceptions.
EPSS: 0.007 (49.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.
Affected products
- Linux — versions 31c6312608c60b72a1feb99a5afb680645a3e8a3, 573e502d14714d2947e22e7eff40ec20a6a44a42, 419ec1b604d7fb60c10aec2dc062371f9fcd4940
- Linux Linux_kernel — versions 7.2
References
Frequently asked questions
- What is CVE-2026-64257?
- CVE-2026-64257 is a critical-severity vulnerability in Linux. CVSS score: 9.1/10. Published 2026-07-25.
- How severe is CVE-2026-64257?
- Critical severity. CVSS v3 base score is 9.1 out of 10.