CVE-2026-31705CRITICAL 9.8EPSS p31.0%
CVE-2026-31705CVE-2026-31705
linux / linux_kernel
Description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix out-of-bounds write in smb2_get_ea() EA alignment
smb2_get_ea() applies 4-byte alignment padding via memset() after
writing each EA entry. The bounds check on buf_free_len is performed
before the value memcpy, but the alignment memset fires unconditionally
afterward with no check on remaining space.
When the EA value exactly fills the remaining buffer (buf_free_len == 0
after value subtraction), the alignment memset writes 1-3 NUL bytes
past the buf_free_len boundary. In compound requests where the response
buffer is shared across commands, the first command (e.g., READ) can
consume most of the buffer, leaving a tight remainder for the QUERY_INFO
EA response. The alignment memset then overwrites past the physical
kvmalloc allocation into adjacent kernel heap memory.
Add a bounds check before the alignment memset to ensure buf_free_len
can accommodate the padding bytes.
This is the same bug pattern fixed
Scoring
| CVSS 3.1 | 9.8 (CRITICAL) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 0.39% probability of exploitation · percentile 31.0% · 2026-06-18T12:00:27Z |
| Published | 2026-05-01 |
| Last modified | 2026-06-01 |
Underlying weaknesses· 1
References
- https://git.kernel.org/stable/c/30010c952077a1c89ecdd71fc4d574c75a8f5617
- https://git.kernel.org/stable/c/790304c02bf9bd7b8171feda4294d6e62d32ae8f
- https://git.kernel.org/stable/c/922d48fe8c19f388ffa2f709f33acaae4e408de2
- https://git.kernel.org/stable/c/98f3de6ef4efbd899348d333f0902dc4ff14380c
- https://git.kernel.org/stable/c/ffbce350c6fd1e99116ea57383b9031717e36d3b
1
| Type | Target | Confidence | Tier |
|---|---|---|---|
| Weakness | Out-of-bounds Writecwe-787 | 0% | live |
Related by meaning· 6
Nearest entities by semantic similarity across the cs-graph corpus.