Vulnerability in Linux
CVE-2026-89632
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr() reparse_buf_ptr() reads buf->ReparseDataLength before checking that count covers the full fixed header: buf = (struct reparse_data_buffer *)((u8 *)io + off); len = sizeof(*buf); /* 8 bytes */ rdlen = le16_to_cpu(buf->ReparseDataLength); /* offset 4, 2 bytes */ if (count < len || count < rdlen + len) /* check comes after */ struct reparse_data_buffer has ReparseDataLength at offset 4. If a server returns OutputCount < 6, the read at offset 4-5 reaches past the end of the received data. The off+count bounds against iov_len were already validated, but that does not protect against count being smaller than sizeof(*buf). Split the check: verify count >= sizeof(*buf) before reading ReparseDataLength, then verify count covers the data region.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.006 (45.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 45.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.001
Affected products
- Linux — versions 6.8, a158bb66b1373866d9fd5997565a58a573085539
References
Frequently asked questions
- What is CVE-2026-89632?
- CVE-2026-89632 is a high-severity vulnerability in Linux. CVSS score: 8.2/10. Published 2026-09-11.
- How severe is CVE-2026-89632?
- High severity. CVSS v3 base score is 8.2 out of 10.