CVE-2026-31478
ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len()
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len() After this commit (e2b76ab8b5c9 "ksmbd: add support for read compound"), response buffer management was changed to use dynamic iov array. In the new design, smb2_calc_max_out_buf_len() expects the second argument (hdr2_len) to be the offset of ->Buffer field in the response structure, not a hardcoded magic number. Fix the remaining call sites to use the correct offsetof() value.
INFO
Published Date :
April 22, 2026, 2:16 p.m.
Last Modified :
April 22, 2026, 2:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-31478
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Apply the latest Linux kernel updates.
- Verify ksmbd buffer management logic.
- Ensure correct offset values are used.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-31478.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-31478 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-31478
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-31478 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-31478 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 22, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len() After this commit (e2b76ab8b5c9 "ksmbd: add support for read compound"), response buffer management was changed to use dynamic iov array. In the new design, smb2_calc_max_out_buf_len() expects the second argument (hdr2_len) to be the offset of ->Buffer field in the response structure, not a hardcoded magic number. Fix the remaining call sites to use the correct offsetof() value. Added Reference https://git.kernel.org/stable/c/0e55f63dd08f09651d39e1b709a91705a8a0ddcb Added Reference https://git.kernel.org/stable/c/4cb537ae4f37d7d0f617815ed4bed7173fb50861 Added Reference https://git.kernel.org/stable/c/6aef1765d6807e0f027cd87f6ac973eb0879a46d Added Reference https://git.kernel.org/stable/c/70b4c414889492c522b6e4331562360f49be2361 Added Reference https://git.kernel.org/stable/c/80824c7e527b70cf9039534e60aff592e8f209d1 Added Reference https://git.kernel.org/stable/c/9a7166f0ef8cbb7bb48dd05e2471d995566003f5 Added Reference https://git.kernel.org/stable/c/c3a89e3ec1ccf64fa6a34e391e1581ebbcba8683