CVE-2026-31478
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 9.8 CRITICAL (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Weakness
- CWE-131
- Record status
- Modified
Affected
- Linux Kernel < 5.15.203
- Linux Kernel < 6.1.168
- Linux Kernel < 6.6.131
- Linux Kernel < 6.12.80
- Linux Kernel < 6.18.21
- Linux Kernel < 6.19.11
- Linux Kernel 6.6
- Linux Kernel 7.0
Attack profile CVSS 3.1 · 9.8
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-31478.md and follow it. Check whether this project is affected by CVE-2026-31478. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- 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
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