CRITICAL: CVE-2026-31478 (CVSS 9.8) — multiple products

CVE: CVE-2026-31478

CVSS: 9.8 (3.1) — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: CRITICAL

Status: Critical advisory

Affected

_See vendor advisory_

Summary

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.

Verified Sources

References

https://git.kernel.org/stable/c/0e55f63dd08f09651d39e1b709a91705a8a0ddcb
https://git.kernel.org/stable/c/4cb537ae4f37d7d0f617815ed4bed7173fb50861
https://git.kernel.org/stable/c/6aef1765d6807e0f027cd87f6ac973eb0879a46d
https://git.kernel.org/stable/c/70b4c414889492c522b6e4331562360f49be2361
https://git.kernel.org/stable/c/80824c7e527b70cf9039534e60aff592e8f209d1
https://git.kernel.org/stable/c/9a7166f0ef8cbb7bb48dd05e2471d995566003f5
https://git.kernel.org/stable/c/c3a89e3ec1ccf64fa6a34e391e1581ebbcba8683

_Validated by the Lyrie Threat Intelligence Pipeline — 3 independent sources confirmed before publication. No speculation._

Lyrie Verdict

A vulnerability of this severity is exactly what Lyrie's anti-rogue-AI defense is built for: continuous, autonomous monitoring that doesn't wait for human reaction time.

#critical