High 7.8Published Jul 19, 2026

CVE-2026-64137smb: client: require net admin for CIFS SWN netlink

Updated under an hour ago (Oct 26, 2026, 10:00 PM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: smb: client: require net admin for CIFS SWN netlink CIFS_GENL_CMD_SWN_NOTIFY is the userspace witness-notify command. The intended sender is the cifs.witness helper, but the generic-netlink operation currently has no capability flag, so any local process can send RESOURCE_CHANGE or CLIENT_MOVE notifications to the in-kernel witness handler. The same family exposes CIFS_GENL_MCGRP_SWN without multicast-group capability flags. Register messages sent to that group include the witness registration id and, for NTLM-authenticated mounts, the username, domain, and password attributes copied from the CIFS session. An unprivileged local process should not be able to join that group and receive those messages. Require CAP_NET_ADMIN for incoming SWN_NOTIFY commands with GENL_ADMIN_PERM, and require CAP_NET_ADMIN over the network namespace for joining the SWN multicast group with GENL_MCAST_CAP_NET_ADMIN. The cifs.witness service runs with the privileges needed for both operations.

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
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: Analyzed
Record last updated: Aug 5, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 before 9cf7eb8919344932f909b2fac76296f7656fda8d; from fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 before 9919021a3b7974ae66a5f9915e3a48c10cfd409b; from fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 before 969bc6370334a5b4720c5470783295d6484bbc95; from fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 before a3238b09c58f323e40743ce174cd0ab81b5c09ed; from fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 before a8d17d22db591099519a89f14dd24810daba74c3; from fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 before c2397b93fbb6f44a788fff30f99be2c20cc5e50f; from fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 before d1ebfce2c1d161186a82e77590bf7da2ea1bce91	CNA record
linux linux_kernel linux:linux_kernel	from 5.11 before 5.15.210; from 5.16 before 6.1.176; from 6.2 before 6.6.143; from 6.7 before 6.12.92; from 6.13 before 6.18.34; from 6.19 before 7.0.11; 7.1; 7.1; and 2 more ranges	NVD

References

References

https://git.kernel.org/stable/c/9cf7eb8919344932f909b2fac76296f7656fda8d	patch
https://git.kernel.org/stable/c/9919021a3b7974ae66a5f9915e3a48c10cfd409b	patch
https://git.kernel.org/stable/c/969bc6370334a5b4720c5470783295d6484bbc95	patch
https://git.kernel.org/stable/c/a3238b09c58f323e40743ce174cd0ab81b5c09ed	patch
https://git.kernel.org/stable/c/a8d17d22db591099519a89f14dd24810daba74c3	patch
https://git.kernel.org/stable/c/c2397b93fbb6f44a788fff30f99be2c20cc5e50f	patch
https://git.kernel.org/stable/c/d1ebfce2c1d161186a82e77590bf7da2ea1bce91	patch

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.