CVE-2026-31432

HIGH
MEDIUM Priority: 0.04 BB Relevance: 68/100
Published: 2026-04-22 Modified: 2026-10-30 First seen: 2026-10-30 Status: active

Attack Surface

Network Low Complexity No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
S: Unchanged
C: High
I: High
A: High

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix OOB write in QUERY_INFO for compound requests When a compound request such as READ + QUERY_INFO(Security) is received, and the first command (READ) consumes most of the response buffer, ksmbd could write beyond the allocated buffer while building a security descriptor. The root cause was that smb2_get_info_sec() checked buffer space using ppntsd_size from xattr, while build_sec_desc() often synthesized a significantly larger descriptor from POSIX ACLs. This patch introduces smb_acl_sec_desc_scratch_len() to accurately compute the final descriptor size beforehand, performs proper buffer checking with smb2_calc_max_out_buf_len(), and uses exact-sized allocation + iov pinning.

Weakness Classification (1)

Affected Software (17)

VendorProductVersion
Linux Linux 9f297df20d93411c0b4ddad7f88ba04a7cd36e77 < 533f84264e28c54a79257ea87d2f94a0fcc9a611
Linux Linux e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < 850452af77f55d185f9445e1f7a1db53c5e4aad4
Linux Linux e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < d48c64fb80ad78b3dd29fb7d79b6ec7bd72bfc09
Linux Linux e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < 075ea208c648cc2bcd616295b711d3637c61de45
Linux Linux e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < 515c2daab46021221bdf406bef19bc90a44ec617
Linux Linux e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < fda9522ed6afaec45cabc198d8492270c394c7bc
Linux Linux f2283680a80571ca82d710bc6ecd8f8beac67d63
Linux Linux 6.1.71 < 6.1.191
Linux Linux 5.15.145 < 5.16
Linux Linux 6.6
linux linux_kernel 5.15.145 – 5.16
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0

Bug Bounty Relevance

68 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

8.8 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploitation Probability

0.51%
Raw Score 0.005070
Percentile 43.2%
Date 2026-10-30

EPSS Trend

2026-10-30
0.00507
2026-10-29
0.00507

Intelligence Sources

mitre ref →
nvd ref →