High 8.8Published Feb 18, 2026

CVE-2026-23230smb: client: split cached_fid bitfields to avoid shared-byte RMW races

Updated under an hour ago (Oct 27, 2026, 7:10 PM ET)

Does this affect you?

It affects Linux and 2 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for Linux

Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: smb: client: split cached_fid bitfields to avoid shared-byte RMW races is_open, has_lease and on_list are stored in the same bitfield byte in struct cached_fid but are updated in different code paths that may run concurrently. Bitfield assignments generate byte read–modify–write operations (e.g. `orb $mask, addr` on x86_64), so updating one flag can restore stale values of the others. A possible interleaving is: CPU1: load old byte (has_lease=1, on_list=1) CPU2: clear both flags (store 0) CPU1: RMW store (old | IS_OPEN) -> reintroduces cleared bits To avoid this class of races, convert these flags to separate bool fields.

CVSS: 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-362
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from ebe98f1447bbccf8228335c62d86af02a0ed23f7 before 569fecc56bfe4df66f05734d67daef887746656b; from ebe98f1447bbccf8228335c62d86af02a0ed23f7 before 4386f6af8aaedd0c5ad6f659b40cadcc8f423828; from ebe98f1447bbccf8228335c62d86af02a0ed23f7 before 3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a; from ebe98f1447bbccf8228335c62d86af02a0ed23f7 before c4b9edd55987384a1f201d3d07ff71e448d79c1b; from ebe98f1447bbccf8228335c62d86af02a0ed23f7 before 4cfa4c37dcbcfd70866e856200ed8a2894cac578; from ebe98f1447bbccf8228335c62d86af02a0ed23f7 before ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241	CNA record
Siemens RUGGEDCOM RST2428P siemens:ruggedcom_rst2428p (from the name)	before V4.0	CISA ADP
linux linux_kernel linux:linux_kernel	from 6.1 before 6.1.164; from 6.2 before 6.6.125; from 6.7 before 6.12.72; from 6.13 before 6.18.11; from 6.19 before 6.19.1	NVD

References

References

https://git.kernel.org/stable/c/569fecc56bfe4df66f05734d67daef887746656b	patch
https://git.kernel.org/stable/c/4386f6af8aaedd0c5ad6f659b40cadcc8f423828	patch
https://git.kernel.org/stable/c/3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a	patch
https://git.kernel.org/stable/c/c4b9edd55987384a1f201d3d07ff71e448d79c1b	patch
https://git.kernel.org/stable/c/4cfa4c37dcbcfd70866e856200ed8a2894cac578	patch
https://git.kernel.org/stable/c/ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241	patch
https://cert-portal.siemens.com/productcert/html/ssa-253495.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.