High 7.8Published Mar 25, 2026

CVE-2026-23393bridge: cfm: Fix race condition in peer_mep deletion

Updated under an hour ago (Oct 27, 2026, 10:23 PM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: bridge: cfm: Fix race condition in peer_mep deletion When a peer MEP is being deleted, cancel_delayed_work_sync() is called on ccm_rx_dwork before freeing. However, br_cfm_frame_rx() runs in softirq context under rcu_read_lock (without RTNL) and can re-schedule ccm_rx_dwork via ccm_rx_timer_start() between cancel_delayed_work_sync() returning and kfree_rcu() being called. The following is a simple race scenario: cpu0 cpu1 mep_delete_implementation() cancel_delayed_work_sync(ccm_rx_dwork); br_cfm_frame_rx() // peer_mep still in hlist if (peer_mep->ccm_defect) ccm_rx_timer_start() queue_delayed_work(ccm_rx_dwork) hlist_del_rcu(&peer_mep->head); kfree_rcu(peer_mep, rcu); ccm_rx_work_expired() // on freed peer_mep To prevent this, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync() in both peer MEP deletion paths, so that subsequent queue_delayed_work() calls from br_cfm_frame_rx() are silently rejected. The cc_peer_disable() helper retains cancel_delayed_work_sync() because it is also used for the CC enable/disable toggle path where the work must remain re-schedulable.

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 dc32cbb3dbd7da38c700d6e0fc6354df24920525 before e89dbd2736a45f0507949af4748cbbf3ff793146; from dc32cbb3dbd7da38c700d6e0fc6354df24920525 before d8f35767bacb3c7769d470a41cf161e3f3c07e70; from dc32cbb3dbd7da38c700d6e0fc6354df24920525 before 1fd81151f65927fd9edb8ecd12ad45527dbbe5ab; from dc32cbb3dbd7da38c700d6e0fc6354df24920525 before 3715a00855316066cdda69d43648336367422127	CNA record
linux linux_kernel linux:linux_kernel	from 5.11.1 before 6.12.78; from 6.13 before 6.18.20; from 6.19 before 6.19.10; 5.11; 7.0; 7.0; 7.0; 7.0; and 3 more ranges	NVD

References

References

https://git.kernel.org/stable/c/e89dbd2736a45f0507949af4748cbbf3ff793146	patch
https://git.kernel.org/stable/c/d8f35767bacb3c7769d470a41cf161e3f3c07e70	patch
https://git.kernel.org/stable/c/1fd81151f65927fd9edb8ecd12ad45527dbbe5ab	patch
https://git.kernel.org/stable/c/3715a00855316066cdda69d43648336367422127	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.